Gold Bullion Development Corp.: Preliminary Metallurgical Testing of Castle Silver Mine Tailings

VANCOUVER, BRITISH COLUMBIA--(Marketwire - June 5, 2008) - Frank Basa, P. Eng, the President of Gold Bullion Development Corp. (TSX VENTURE:GBB) (the "Company") announces that the Company has completed preliminary metallurgical testing on a grab composite sample of silver tailings material extracted from the tailings pond at the Castle Silver Mine in Gowganda, Ontario. The test results indicate that it responds to gravity processing conditions. The sample used for testing was a composite made up of several grabs samples taken at depth from one of the tailings ponds. The combined sample weighed in about 100 kilograms. The head assay of the test composite sample obtained was 293.88 grams per tonne silver (8.57 ounces per ton silver) 0.132 percent cobalt and 0.467 percent arsenic. After gravity concentration, the concentrate grade assayed 8408.75 grams per tonne silver (245.25 ounces per ton silver) 2.12% cobalt and 12.64% arsenic. The higher-grade silver concentrate may also result in cobalt returns.

The Castle Silver Mine property is 100% owned by the Company and located 85 kilometres northwest of the silver camp in Cobalt, Ontario. The property consists of 34 leased mining claims and two licences comprising several disconnected groups located in the Haultain and Nicol Townships, Larder Lake Mining Division, District of Timiskaming, Ontario, covering approximately 564.4 hectares. There are three mine shafts numbered one, two and three with respective depths of 149 metres, 140 metres and 259 metres with excellent infrastructure and access to power. Access to the various properties can be readily gained by secondary roads that extend northward from Highway #560.

The 1989 Cobalt Residents Geologist's District report says the Castle mine, in operation since 1917, produced 763,127,010 grams of silver (22.26 million ounces of silver) from the No. 3 shaft to 1989. Recent production from Agnico-Eagle Mines Ltd. for the Castle mine during the 1979 to 1989 term was as follows: 101,024 tonnes milled, 91,421,294 grams silver (2.67 million ounces of silver), 34,597 kilograms cobalt and 10,180 kg copper.

The result are extremely encouraging and indicates that by means of gravity processing the tailings, it is possible to produce a high grade silver concentrate. The assays were done at Swastika Laboratories Ltd. The test program was supervised by Frank J Basa, P.Eng, a qualified person as per National Instrument #43-101, who has also reviewed this release.

For more information on Gold Bullion Development Corp. (TSX VENTURE:GBB), visit our website http://www.goldbulliondevelopmentcorp.com/en/.

ON BEHALF OF THE BOARD OF DIRECTORS

Frank J. Basa, P.Eng., President

This press release has been prepared by management.

The TSX Venture Exchange has not reviewed and does not accept responsibility for the adequacy or accuracy of this release.