Naphthalene esters have been reduced over a nickel-on-kieselguhr catalyst which gives specific reduction to the tetrahydronaphthalene (tetralin) stage. The method is of practical utility, since no monitoring of the hydrogen uptake is necessary.THE LITERATURE contains much information on the reduction of naphthalene and its derivatives to the corresponding tetralin and its derivatives. Nickel catalysts have been prevalent in the reported work (1, 4, 9, 10), though platinum (4) and copper chromite (2, 6) catalysts have also been used.