A process for preparing a polyamide by reacting a mixture which comprises a monomer which has a nitrile group and has at least one other functional group capable of forming a carboxamide group, and comprises water, in the presence of titanium dioxide as catalyst, which comprises using titanium dioxide whose BET surface area, determined to the German standard DIN 66 131 volumetrically by the multipoint method, is in the range from 5 to 35 m.sup.2/g.