Guyana Goldfields Significantly Increases Mineral Resources and Grade at the Aurora Gold Project, Guyana

TORONTO, February 28, 2011 - Guyana Goldfields Inc. (TSX: GUY) ("Guyana" or "the Company") is pleased
to report an updated mineral resource statement for its 100% owned Aurora
Gold Project in Guyana, South America. This new estimate includes all
drilling data obtained up to the end of November 2010. The estimate was
prepared by SRK Consulting (Canada), Inc. ("SRK") of Toronto, Ontario in
accordance with National Instrument 43-101 ("NI 43-101") and provides an
update to the previous estimate released on August 24, 2009. The next
estimate is scheduled to be released in August 2011 and will incorporate
drilling up to June. The Feasibility Study is scheduled for completion during
the fourth quarter and will be based upon the August 2011 resource estimate.

Highlights

    - 80% of all mineral resources are in the measured and indicated category
      (5.34 million ounces) and 20% are in the inferred category (1.33
      million ounces)

    - 66% increase in measured and indicated mineral resources from 3.21 to
      5.34 million ounces

    - 64% increase in open pit measured and indicated mineral resources from
      1.19 to 1.95 million ounces

    - 67% increase in underground measured and indicated mineral resources
      from 2.03 to 3.39 million ounces

    - 17% increase in open pit grade from 3.0 to 3.6 g/t Au

    - 3 % increase in total overall grade from 3.8 to 4.0 g/t Au

"This significant increase in mineral resources and the likelihood of
more ounces being added with the additional drilling planned for this year
support our organic growth strategy and should significantly enhance the
economics of the Definitive Feasibility Study, which is currently underway.
The positive impact of the 2009/2010 drilling campaigns which discovered and
extended various zones at depth within the Golden Square Mile is finally
reflected in the new resource numbers. We remain very confident that this
already robust project will continue to grow and soon join the ranks of
world-class producing gold mines." said Mr. Claude Lemasson, President &
Chief Operating Officer.

Mineral Resource Drilling Data

The updated mineral resource statement incorporates drilling data
consisting of:

    - Drilling for the Preliminary Assessment completed in August 2009
      totaling 140,442 metres with drilling data up to June 2, 2009

    - Infill and exploration drilling completed from June 3, 2009 to November
      21, 2010 totaling an additional 79,446 metres, during which new
      mineralized zones were discovered beneath the Aleck Hill and Mad Kiss
      shallow zones (see press releases dated April 20, 2010 and August 18,
      2010)

    - The new mineral resource statement contains a total of 209,000 metres
      of drilling in 776 holes.

Resource Estimate Comparison

    February 2011 

    Gold Price     Tonnes    Grade   Gold    % Change
      (US$)        (000 t)   (g/t) (000 oz)
    $1,040/oz       

    O/P   

    M&I           17,277      3.51   1,947      64.3%
    Inf            3,533      3.74     425       8.0%    

    U/G
    M&I           24,894      4.24   3,394      67.5%
    Inf            6,898      4.10     910      -6.5%     

    O/P & U/G
    M&I           42,171      3.94   5,341      66.3%
    Inf           10,432      3.98   1,334      -2.3%     

    TOTAL         52,603      3.95   6,675      45.8%   

    *Cutoff grade: 0.45 g/t Au for O/P and
     2.0 g/t Au for U/G. 

    (Table continued)

    August 2009  

    Gold Price     Tonnes    Grade   Gold
      (US$)        (000 t)   (g/t) (000 oz)
    $750/oz

    O/P
    M&I           11,136      3.31   1,185
    Inf            5,013      2.44     393

    U/G
    M&I           13,010      4.85   2,027
    Inf            7,931      3.82     973

    O/P & U/G
    M&I           24,146      4.14   3,212
    Inf           12,944      3.28   1,366

    TOTAL         37,090      3.84   4,578  

    *Cutoff grade: 0.85 g/t Au for O/P and
     2.0 g/t Au for U/G.

Note: The following references are made: Open pit = O/P; Underground =
U/G, Measured and Indicated = M&I; Inferred = Inf

Mineral Inventory

The new resource estimate is based on a mineral inventory. The table
below summarizes the global tonnes and grade estimates in the block model
constructed by SRK at various cut-off grades. It is to be noted that the
figures presented in the following table should not be misconstrued with the
mineral resource statement presented in the table above. They are presented
only to illustrate the sensitivity of the global tonnes and grade estimates
to the selected cut-off grades.

    Measured and Indicated Resources within Mineral Inventory
      COG         Tonnes       Grade       Gold
     (g/t)         (000)       (g/t)     (000 oz)
      0.3         51,452       3.49        5,770
      0.4         51,239       3.50        5,760
      0.5         50,887       3.52        5,760
      0.6         50,488       3.54        5,750
      0.7         49,898       3.58        5,740
      0.8         49,372       3.61        5,730
      0.9         48,614       3.65        5,700
      1.0         47,879       3.69        5,680
      2.0         36,706       4.34        5,130
      3.0         23,572       5.38        4,080                                   

    Inferred Resources within Mineral Inventory
      COG         Tonnes       Grade       Gold
     (g/t)         (000)       (g/t)     (000 oz)
      0.3         14,539       3.17        1,480
      0.4         14,451       3.19        1,480
      0.5         14,268       3.22        1,480
      0.6         14,020       3.27        1,470
      0.7         13,788       3.32        1,470
      0.8         13,480       3.38        1,460
      0.9         13,074       3.45        1,450
      1.0         12,712       3.52        1,440
      2.0          9,029       4.37        1,270
      3.0          5,953       5.34        1,020

Note: COG references cut off grade; selected cut off grades are shown.
The reader is cautioned that the numbers presented in the table above should
not be misconstrued with the mineral resource statement. They are presented
only to show the sensitivity of the global quantity and grade estimates to
the selection of cut-off grades.

A total 2011 budget of $20 million is being allocated for drilling at
Aurora. Ten (10) drill rigs are operational with the goal of drilling 70,000
metres by the end of June. This drilling aims to further convert inferred to
measured & indicated resources during the first half of the year. Exploration
drilling will continue for the remainder of the year and is designed to
significantly increase the discovery potential of local and regional
mineralized trends and recently identified zones.

Currently there are over 20 geologists working at both Aurora and the
Company's Aranka properties. The Company continues its assessment of the
possibility of including Sulphur Rose and its initial resource of 460,400
ounces (see press release dated December 31, 2010) into the Aurora
Feasibility Study due to its proximity and similar metallurgical character.
Two (2) drills are operating at Sulphur Rose dedicated to carry out
exploration and infill drilling in order to confirm additional resources.

"We are very pleased by the drilling success and the increase in mineral
resources. We are also continuing infrastructure construction activities at
site and will be in a position to start the mine development process in the
fourth quarter of this year after the completion of the Feasibility Study.
The Aurora Gold Project will make a significant contribution to the economy of
Guyana with gold production expected to commence in late 2013." stated Mr.
Lemasson.

The Aurora exploration and infill drilling programs are being carried out
under the supervision of Mr. Niel Silvio (Aus.IMM), a qualified person within
the meaning of NI 43-101. Mr. Silvio has reviewed the contents of this news
release.

The resource estimate was prepared by SRK resource estimation specialists
Dorota El-Rassi P.Eng (APEO #100012348) and Glen Cole, P.Geo (APGO #1416) who
are the independent "Qualified Persons" for the Purposes of NI 43-101,
Standards of Disclosure for Mineral Projects of the Canadian Securities
Administrators, and confirm that they have reviewed the information contained
within this release.

Drill core samples for the 2009/2010 drilling campaigns were sent to and
prepared at ACME Analytical Laboratories Ltd (ACME Lab) in Georgetown, Guyana
while assaying was done at ACME Lab in Santiago, Chile.

About SRK Consulting

SRK Consulting is an independent, international consulting practice that
provides focused advice and solutions to clients, mainly from earth and water
resource industries. The SRK Group comprises over 1,000 professionals in 36
offices worldwide, offering expertise in a wide range of resource engineering
disciplines. The SRK Group's independence is ensured by the fact that it
holds no equity in any project and that its ownership rests solely with its
staff. This permits SRK to provide its clients with conflict-free and
objective recommendations on crucial judgment issues. SRK has a demonstrated
track record in undertaking independent assessments of Mineral Resources and
Mineral Reserves, project evaluations and audits, technical reports and
independent feasibility evaluations to bankable standards on behalf of
exploration and mining companies and financial institutions worldwide.

About Guyana Goldfields Inc.

Guyana Goldfields Inc. is a Canadian based mineral exploration company
primarily focused on the exploration and development of gold deposits in
Guyana, South America where the Company has operated since 1996. The Company
is currently undertaking drilling and studies to advance and develop the
Aurora Gold Project in Guyana.

At the Aranka Properties, currently in advanced staged exploration,
drilling of highly prospective targets is ongoing. The Company discovered a
new gold zone at Sulphur Rose and identified an initial resource of 460,000
ounces. As at the date hereof, the Company has approximately $60 million in
cash and short-term bank guaranteed investment certificates and no debt;
there are 82 million shares issued and outstanding.

Forward Looking Statements - Certain information set forth in this news
release may contain forward-looking statements that involve substantial known
and unknown risks and uncertainties. These forward-looking statements are
subject to numerous risks and uncertainties, certain of which are beyond the
control of Guyana, including, but not limited to the impact of general
economic conditions, industry conditions, volatility of commodity prices,
risks associated with the uncertainty of resource and reserve estimates,
currency fluctuations, dependence upon regulatory approvals, the availability
of future financing and exploration risk. Readers are cautioned that the
assumptions used in the preparation of such information, although considered
reasonable at the time of preparation, may prove to be imprecise and, as such,
undue reliance should not be placed on forward-looking statements.

%SEDAR: 00022477E

    For further information:

    Guyana Goldfields Inc.,
    Claude Lemasson, President & COO, Director
    Jacqueline Wagenaar,
    Vice President, Corporate Communications
    Tel: +1-416-628-5936 Ext. 2295,
    Fax: +1-416-628-5935,
    E-mail: jwagenaar@guygold.com,
    Website: www.guygold.com

For further information: Guyana Goldfields Inc., Claude Lemasson, President & COO, Director, Jacqueline Wagenaar, Vice President, Corporate Communications; Tel: +1-416-628-5936 Ext. 2295, Fax: +1-416-628-5935, E-mail: jwagenaar at guygold.com