Continuation therapy using intermittent chemotherapy and BCG inoculation was commenced in 28 children with acute lymphocytic leukemia (ALL) immediately after remission induction and "CNS prophylaxis." At a median followup time of 17 months, 71% remain in total remission and 86% in bone marrow remission. Complications of the therapy were minimal. Major infections occurred on two occasions and there were no deaths in remission. Neutropenia, "minor" infections and postponement of chemotherapy occurred most often during the first three courses of treatment. There were no local or systemic BCG infections. Tuberculin sensitivity was tested in 25 patients. It was positive in 17 of 18 patients in total remission and all four patients with only CNS relapse, and was negative prior to relapse in three patients who developed bone marrow disease.