Aromatic or heteroaromatic nitro compounds are catalytically hydrogenated to the corresponding amines in the presence of a platinum catalyst comprising elemental platinum on a support; the platinum catalyst is modified with a molybdenum compound and a phosphorus compound wherein the phosphorus has an oxidation state of less than +5, e.g. hypophosphorous acid; the catalyst is particularly useful in the hydrogenation of nitro compounds with halogen and/or sulfur-containing substituents.