Abstract: A process for the production of butane-1,4-diol comprises hydrogenating a di(C.sub.1 to C.sub.3 alkyl) ester of a C.sub.4 dicarboxylic acid, e.g. an ester of a but-2-en-1,4-dioic acid, such as diethyl maleate, in the vapor phase at a temperature of from about 150.degree. C. to about 240.degree. C. and at a pressure in the range of from about 25 bar to about 75 bar in the presence of a reduced copper chromite catalyst, and recovering resulting butane-1,4-diol containing reaction product. The catalyst contains, before reduction, from about 25 to about 45% by weight of copper and from about 20 to about 35% by weight of chromium and preferably has an internal surface area of at least about 30 sq. m. per gram. The process is preferably conducted in two or more reaction zones, which are preferably operated adiabatically, the feed temperature to the first zone being higher than that to at least one subsequent reaction zone.