Agoracom

VANCOUVER, BC- August 21, 2007 - Portrush Petroleum Corporation (OTCBB: PRRPF) (TSX VENTURE: PSH) wishes to announce that field operations have begun in preparation to drill the next well on the Mission River lease. The well will be drilled to a depth of 7,950 feet and is anticipated to take approximately fourteen days to drill.

Four drilling units (40 acres per unit) are being surveyed and a "Permission To Drill" application for the first location is being prepared for filing with the Texas Railroad Commission in Austin, Texas. This well location will be constructed immediately and the operator is working with the drilling rig company to schedule the rig move to the drillsite.

The operator anticipates drilling the first well will confirm the results of the 3-D seismic data shot in December 2006 and January 2007 and thoroughly reviewed since the completion of the Scanio Sheldon No. 8 drilled earlier this year. The re-worked seismic clearly identifies the intended payzones expected to be penetrated by this first well. A successful well would then be followed by three additional wells.

The Mission River lease is being developed by McAlester and is located at the south end of the town of Refugio, Refugio County, Texas. The field has multiple pays at depths ranging from 2,000 to 8,800 feet. Portrush has a 10% working interest in the field. To date nine wells have been drilled and all nine wells have been placed on production.

About Portrush Petroleum Corporation:

Portrush Petroleum is a rapidly growing oil and natural gas exploration and production company focused on its core properties: the Lenox project, located in the Michigan Basin of the state of Michigan, and the Mission River Development project, situated in Refugio and Goliad Counties, Gulf Coast, Texas.

To find out more about Portrush Petroleum Corporation visit our website at www.portrushpetroleum.com

ON BEHALF OF THE BOARD
Mr. Martin Cotter
President & Director

The TSX Venture Exchange has not reviewed this press release and has neither approved nor disapproved the information contained in this press release. The statements made in this Press Release may contain forward-looking statements that may involve a number of risks and uncertainties. Actual events or results could differ materially from the Company's expectations and projections.

CONTACT INFORMATION
Portrush Petroleum Corporation
Telephone
604 696 2555
866 939 2555
info@portrushpetroleum.com