The effects of different chemotherapy protocols on survival were evaluated in 197 small cell lung cancer patients followed-up between 1974 and 1987 in our unit. Of these, 170 patients had Stage IV disease and 24 had Stage III disease. Thoracic radiotherapy was given to 73 patients of whom 63 had Stage IV disease. Cytotoxic chemotherapy was given in four main protocols consisting of cyclophosphamide (CYC): CYC + vincristine (VCR); CYC + VCR + adriamycin (ADM) and CYC + VCR + ADM + lomustine (CCNU). The latter protocol was associated with the highest survival rates and differed significantly (p less than 0.05) from the others. In patients with extensive disease, both radiotherapy to the primary site and adjuvant immunomodulation in conjunction with the above chemotherapy regimens lacked any beneficial effect on survival.