Treatment with BCG (Bacillus Calmette-Guérin) followed by irradiation was attempted to improve response to therapy by cutaneous metastases from malignant skin melanomas. Both agents were applied in low doses, known to cause minimal side effects. Nineteen patients, divided into three groups, entered the clinical trial. The first group consisted of five patients with relatively large metastases that usually appeared as a residual disease in the surgically treated area. Five patients with numerous, large metastases were included in the third group. The treatment sequence consisted of applying BCG intralesionally in doses from 4 x 10(5) to 1.17 x 10(7) viable units. After a free interval, the affected area was irradiated with doses from 1500--2500 ret. Patients with numerous small metastases and those with a small number of larger metastases, i.e., patients of the first and second group, showed a complete response and in these cases regression affected all the noninjected nodules and was also effective when regression could not have been achieved by BCG alone.