Butane-1,4-diol is prepared by catalytic hydrogenation of dibutyl succinate by a process in which hydrogenation is terminated before complete conversion is reached, butanol is distilled off from the reaction mixture, the liquid distillation residue is cooled to below 108.degree. C., the upper phase, which is formed as a result of phase separation and essentially consists of dibutyl succinate, is recycled to the hydrogenation, and the butane-1,4-diol is obtained from the lower phase, which essentially consists of this compound, by fractional distillation under reduced pressure.