Cryosurgery was used for treatment of recurrent proliferative keratoconjunctivitis in 5 dogs that had been treated with combined medical and surgical procedures without success. Four dogs recovered completely after one application of cryosurgery. The fifth dog did not respond to cryosurgery until after oral administration of corticosteroids was stopped, indicating a possible immune-mediated mechanism of action of cryosurgery on proliferative keratoconjunctivitis.