Remission duration associated with the administration of conventional maintenance chemotherapy to patients with acute myelogenous leukaemia was evaluated. The records of 760 patients who entered remission between 1974 and 1979 were reviewed. The median duration of remission was 1.1 years with 16% of patients remaining in remission at 8 years. The relapse curve was biphasic with a high rate of relapse during the first 2 1/2 years of remission followed by a much lower relapse rate thereafter. Leukaemic relapses were noted through 8 years of remission. A plateau phase indicating freedom from the risk of leukaemic recurrence is not clearly apparent yet but may exist after the eighth year of remission.