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 the evaluation of the scientific literature are described separately (Acta Oncol 2001; 40: 155-65). This overview of the literature on aggressive, high grade non-Hodgkin's lymphoma (NHL), chiefly diffuse large B-cell lymphomas, is based on 111 scientific articles, including 35 randomised trials, 44 prospective studies and 11 retrospective studies, including totally 21,830 treated patients. The conclusions reached can be summarised into the following points: For patients with localised aggressive NHL (stage I and non-bulky II) a combination of chemo- and radiotherapy will result in cure for a large proportion of patients. For a subgroup of patients with stage I non-bulky disease and without risk factors, local radiotherapy alone is also adequate treatment. For patients with disseminated aggressive NHL, including the elderly, the CHOP-regimen remains the standard primary chemotherapy. In an unselected population, this treatment cures about one third of the patients. For most patients with poor prognostic factors, CHOP provides insufficient results. The results of therapy with dose-intensive combinations of cytotoxic drugs have been conflicting. Most randomised studies, using intensive regimens as first line therapy, have failed to show any benefit in comparison to CHOP. However, it is possible that regimens other than CHOP might be more beneficial in subgroups with 'high risk' disease. This remains to be investigated in prospective studies. In young, poor prognosis, patients a further intensified induction therapy requiring haematopetic stem cell support, i.e. high dose therapy, has been suggested to be beneficial. The best results have been reported from studies with full course standard induction followed by high-dose therapy. However, the study data are conflicting, which is why additional controlled studies are recommended. In patients refractory to or relapsing after initial therapy, different chemotherapy combinations may induce a new response. The responses are, however, rather short-lived and long-term survival is rarely seen. In patients not attaining complete remission after initial standard therapy, high-dose therapy with stem cell support may improve the response, but the impact on survival is not established. In patients refractory to initial standard therapy there is no evidence for a survival prolongation from high-dose therapy with stem cell support, although a subset of patients might benefit. For patients with chemosensitive relapse, salvage therapy followed by high-dose therapy with stem cell support is recommended, since this may result in prolonged survival.