Acetone cyanohydrin was found to be a facile, convenient and comparatively safer alternative to toxic sodium cyanide/acetic acid system for generating in situ HCN for the oxidative cyanation of tertiary amines to alpha-aminonitriles in high yields with hydrogen peroxide using RuCl3 as catalyst. In addition organic nature of acetone cyanohydrin makes it more suitable for an organic transformation since it is readily soluble in reaction medium and can be added in a controlled manner.