In two centers (a comprehensive cancer center and a university hospital) 1300 patients with non-Hodgkin's lymphomas (NHL) were observed during the past 15 years. Seventy patients (5.4%) were diagnosed after they were 80 years old. Thirty-four patients had low-grade NHL, eight had intermediate grade, and 28 had high-grade NHL. The majority of them were classified as Stage I (n = 24) or II (n = 18), and the rest as Stage III (n = 16) or IV (n = 12). Treatment varied with grade of NHL, tumoral extension, and performance status. Forty-seven patients were given chemotherapy, 37 radiotherapy, and six patients had surgery. Overall, treatment was considered to be optimal in 12 patients, good in 34 patients, and limited in 24 patients. Toxicity was minimal in 62 patients, treatment-limiting in two patients, and lethal in six patients. Thirty-seven patients achieved a complete remission (CR), 21 a partial remission, five experienced stabilization, and seven failed to respond. For all patients, the median survival (MS) was 18 months. In contrast to younger patients, malignancy grade had no significant influence. The only significant parameter is CR (P = 0.02). In conclusion, very old patients must be treated correctly but carefully. Better tolerated treatments are needed to improve results that are neither very poor nor as good as in younger patients.