NOT FOR DISTRIBUTION TO U.S. NEWSWIRE SERVICES OR FOR RELEASE, PUBLICATION, DISTRIBUTION OR DISSEMINATION DIRECTLY, OR INDIRECTLY, IN WHOLE OR IN PART, IN OR INTO THE UNITED STATES.

Vancouver, BC – May 5, 2015 – NexGen Energy Ltd. (TSX-V: NXE) ("NexGen" or the "Company") is pleased to announce that it has entered into a revised agreement with a syndicate of investment dealers co-led by Cormark Securites Inc. and Cantor Fitzgerald Canada Corporation and including Dundee Securities Ltd. And Haywood Securities Inc. (collectively the “Underwriters”) under which the Underwriters have now agreed to purchase a total of 47,480,000 common shares of the Company (the “Shares”), on a bought deal basis, at a price of C$0.50 per Share for gross proceeds of C$23,740,000 (the “Offering”).

In addition, the Company has agreed to grant to the Underwriters an option to purchase up to an additional 15% of the number of Shares sold under the Offering at a price of C$0.50 per Share, on the same terms and conditions as the Offering, exercisable at any time, in whole or in part, until the date that is 30 days following the closing of the Offering. In the event that the option is exercised in its entirety, the aggregate gross proceeds of the Offering to NexGen will be approximately C$27,301,000.

The net proceeds of the Offering will be used to advance the exploration and development of the Company’s mineral properties located in Saskatchewan, Canada and for working capital and general corporate purposes.

The Shares to be issued under the Offering will be offered by way of a short form prospectus in all of the provinces of Canada, other than the Province of Quebec.

The Offering is scheduled to close on or about May 26, 2015 and is subject to certain conditions including, but not limited to, the receipt of all necessary regulatory and other approvals including the approval of the TSX Venture Exchange and the securities regulatory authorities.

The securities offered have not been, and will not be, registered under the U.S. Securities Act of 1933, as amended (the "U.S. Securities Act") or any U.S. state securities laws, and may not be offered or sold in the United States or to, or for the account or benefit of, United States persons absent registration or any applicable exemption from the registration requirements of the U.S. Securities Act and applicable U.S. state securities laws. This press release shall not constitute an offer to sell or the solicitation of an offer to buy securities in the United States, nor shall there be any sale of these securities in any jurisdiction in which such offer, solicitation or sale would be unlawful.

About NexGen:

NexGen is a British Columbia corporation with a focus on the acquisition, exploration and development of Canadian uranium projects. NexGen has a highly experienced team of uranium industry professionals with a successful track record in the discovery of world class uranium deposits and in developing projects through discovery to production.

NexGen owns a portfolio of highly prospective uranium exploration assets in the Athabasca Basin, Saskatchewan, Canada, including a 100% interest in Rook I, location of the Arrow Discovery in February 2014 and Bow Discovery in March 2015.

The technical information in this news release has been prepared in accordance with the Canadian regulatory requirements set out in National Instrument 43- 101 and reviewed on behalf of NexGen Energy Ltd., by Garrett Ainsworth, P.Geo., Vice President – Exploration & Development, a qualified person.

Leigh Curyer

Chief Executive Officer

NexGen Energy Ltd.

+1 604 428 4112

lcuryer@nexgenenergy.ca

nexgenenergy.ca

For further information, please contact:

Kin Communications

Tel: 604 684 6730

Toll Free: 1 866 684 6730

Email: nxe@kincommunications.com

Website: nexgenenergy.ca

The TSXV has neither approved nor disapproved the contents of this press release. Neither the TSXV nor its Regulation Services Provider (as that term is defined in the policies of the TSXV) accepts responsibility for the adequacy or accuracy of this release.

Forward-Looking Statements

This news release contains "forward-looking information" within the meaning of applicable Canadian securities laws. Generally, but not always, forward looking information is identifiable by the use of words such as “will” and planned” and similar expressions. Forward-looking information is based on the then current expectations, beliefs, assumptions, estimates and forecasts about the Company’s business and the industry and markets in which it operates. Such information is not a guarantee of future performance and undue reliance should not be placed on forward-looking information. Assumptions and factors underlying the Company’s expectations regarding forward-looking information contained herein include, among others: that general business and economic conditions will not change in a material adverse manner; that financing will be available if and when needed on reasonable terms; that the Company’s current exploration activities can be achieved and that its other corporate activities will proceed as expected; that third party contractors, equipment and supplies and governmental and other approvals required to conduct the Company’s planned exploration activities will be available on reasonable terms and in a timely manner.

Although the assumptions made by the Company in providing forward looking information are considered reasonable by management at the time the forward-looking information is given, there can be no assurance that such assumptions will prove to be accurate. Forward-looking information also involves known and unknown risks and uncertainties and other factors, which may cause actual events or results in future periods to differ materially from any projections of future events or results expressed or implied by such forward-looking information, including, among others: risks related to the availability of financing on commercially reasonable terms and the expected use of the proceeds; changes in the market; potential downturns in economic conditions; industry conditions; actual results of exploration activities being different than anticipated; changes in exploration programs based upon results of exploration; future prices of metal; availability of third party contractors; availability of equipment and supplies; failure of equipment to operate as anticipated; accidents, effects of weather and other natural phenomena and other risks associated with the mineral exploration industry; environmental risks; changes in laws and regulations; community relations; and delays in obtaining governmental or other approvals or financing. There can be no assurance that forward-looking information will prove to be accurate, as actual results and future events could differ materially from those anticipated, estimated or intended. NexGen undertakes no obligation to update or reissue forward-looking information as a result of new information or events except as required by applicable securities laws. The reader is cautioned not to place undue reliance on forward-looking information.