In order to assess the progress and limitation of chemotherapy in the treatment of small cell lung cancer in the elderly, we analyzed 218 patients who had entered into protocol studies between 1982 and 1990. Among those, there were 101 elderly patients (age of greater than or equal to 66 years) and 117 non-elderly patients (age of less than or equal to 65 years). Response to chemotherapy with or without chest irradiation was almost comparable for the elderly and the non-elderly; complete response rate was 52% for limited disease (LD) and 33% for extensive disease (ED) in the elderly, and it was 68% for LD and 23% for ED in the non-elderly. Survival figures of the two groups were quite similar: The median survival time was 12.6 months for the elderly and 14.5 months for the non-elderly, and the 3-year survival rate was 14% for both groups. An improvement of patient survival was observed along with the chronology of the protocols, i.e., with a escalation of dose intensity. Of interest, the improvement was rather evident in the elderly than in the non-elderly. Hematologic toxicity was considerable more frequent and severe in the elderly than in the non-elderly with non-significant statistics. The incidense of fever episodes while neutropenic was significantly more frequent in the elderly. Non-hematologic toxicity was almost comparable for the two groups, with a exception that the elderly showed a trend being predisposed to renal toxicity. In conclusion, such elderly patients as eligible for entry into a protocol study can benefit from intensive treatment as equally as non-elderly patients can.