The writer, as medical director of Father Damien Leper Colony (Ubá, Minas Gerais, Brasil), treated 50 cases of perforating ulcers, from 2 to 40 years of duration, using the antigens prepared with acid-fast bacilli cultures obtained from leprous material by Dr. H. C. de Souza-Araujo. Dosage from 0,12 to 39,35 cm3, injected inside the ulcers, intramuscularly, every 2 to 4 days, accordingly to the patient reaction some of them presenting fever until 41° Centigrade. The result was cicatrization of the ulcers in 92% (46 out of 50) of the patients. The author concluded that the majority of his patients tolerate perfectly the medicine and that its efect was very eficient.