Disclosed is a process for the preparation of 1,2-glycols by hydrogenation of 1,2-dioxygenated organic compounds in the presence of a catalyst composition comprising a ruthenium compound, a trivalent phosphorus compound selected from 1,1,1-tris(diarylphosphinomethyl)alkyl or substituted alkyl, and a promoter selected from Lewis acids, protic acids having an ionization constant (K.sub.i) of 5.times.10.sup.-3 or greater, and onium salts. The process is useful for the hydrogenation of glycolic acid or derivatives thereof to ethylene glycol.