109 patients with advanced stage non-Hodgkin lymphomas were treated with cytostatic chemotherapy. 91 of these patients were classified according to the Kiel classification as having lymphomas of low-grade malignancy, whilst the remaining 18 had lymphomas of high-grade malignancy. The primary treatment in low-grade malignant lymphomas was a combination of chlorambucil and prednisone: in case of progression or therapeutic failure more aggressive schedules (COP, C-MOPP, HOP, CHOP, BACOP) were used. Patients with high-grade malignant lymphomas were treated in the first instance according to these aggressive schedules. Although no complete remissions were achieved, 25 out of the 47 patients with CLL responded with a partial remission to chlorambucil/prednisone, whilst 12 out of 19 non-responders to this schedule reacted favourably to COP. The results in 10 patients with immunocytic lymphomas were of a similar order. Better results were achieved in patients with germinal centre tumours: 9 out of the 11 patients with centrocytic lymphomas and all 20 patients with centrocytic-centroblastic tumours responded with a complete or partial remission. Of 18 patients with high-grade malignant lymphomas, 5 responded with a complete remission, 8 with a partial remission.