A general catalytic and relatively environment friendly method for beta-epoxidation of Delta(5)-steroids has been developed, which uses silica supported cobalt as catalysts and molecular oxygen as the oxidant. The reactions are regio- and stereoselective. A whole range of Delta(5)-steroids, with different functional groups such as hydroxyl, carbonyl or acetyl, as well as different side chains, were conveniently converted to the corresponding biologically interesting 5beta,6beta-epoxides with high degree of stereoselectivity and high yields. (C) 2004 Elsevier B.V. All rights reserved.