The proportion of patients with vasculitis and rapidly progressive nephritis aged 70 years or over has risen from about 10% in the 1980s to over 30% in series reported in the 1990s. This study was undertaken to examine the presentation and outcome of such older patients. Seventeen of 56 patients (30%) who presented at two renal units were aged 70 years or over. Mean creatinine level at presentation was 530 mumol/l, and five patients received dialysis at presentation. Outcome was dependent on three factors, namely comorbid pathology, response to immunosuppressive therapy, and the occurrence in three cases of temporary spontaneous partial remission. Overall patient survival at one and two years was 62.5% and 50%, respectively, and 90% and 100% of surviving patients were independent of dialysis at one and two years, respectively. Response to chemotherapy was excellent, with full rehabilitation in many cases and no deaths directly attributable to adverse effects of immunosuppressive therapy. We conclude that diagnosis of vasculitis and rapidly progressive glomerulonephritis by renal biopsy and the subsequent administration of chemotherapy (including cyclophosphamide in many cases) resulted in a worthwhile benefit in these elderly patients.