Cryosurgery, with temperatures ranging from -40 C to -140 C, was performed on 32 developing mandibular third and fourth premolar buds of dogs. Evaluations were made on clinical, radiographic, and histologic bases at prescribed time intervals. There was complete inhibition of odontogenesis in 62.5% of third premolars and 25% of fourth premolars. There was 25% partial inhibition of third premolars and a 56.25% inhibition of fourth premolars. The adjacent developing tooth buds and bone were not affected.