A systematic review of chemotherapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for evaluation the scientific literature are described separately (Acta Oncol 2001; 40: 155-65). This synthesis of the literature on chemotherapy for indolent non-Hodgkin's lymphoma (NHL), predominantly follicular lymphoma, is based on 108 scientific reports including 31 randomised studies, 38 prospective studies and 18 retrospective studies. These studies involve 8,699 patients. The conclusions reached can be summarized into the following points: In initially localized disease-- The addition of chemotherapy to radiotherapy as primary treatment has not convincingly prolonged remission duration or survival. In initially advanced disease-- Alkylating agents are useful palliative treatment options which can result in improved well-being for most patients, often for long periods. Combinations of chemotherapy have not convincingly resulted in more or longer remissions. There is no proof that initial combination chemotherapy will prolong survival in comparison with single drugs. The addition of interferon to initial combination chemotherapy may increase the response rate, significantly prolong remission duration, but prolonged survival has not been unequivocally proven. In the absence of disease-related symptoms, treatment can safely be deferred. For patients with relapsed lymphoma-- Patients may repeatedly respond to alkylating agents or combinations containing an alkylating agent, although the proportion responding decreases with each relapse. Patients relapsing after or who are refractory to treatment with alkylating agents often respond to treatment with combinations containing an anthracycline. Responses are also often seen in patients treated with purine analogues alone or in combination with other drugs. High dose chemotherapy followed by autologous or allogeneic reestablishment of bone marrow function can induce long-term remissions but it is not proven whether they are more frequent or of longer duration than with conventionally dosed therapy. The impact of the novel treatment strategies including high-dose therapy on overall survival is still uncertain. A monoclonal antibody, rituximab, is a new active substance for patients with relapsed lymphoma. It can induce remissions also in chemoresistant patients.