We tested the efficacy of maintenance treatment with alpha-2a interferon, 1 megaunit thrice weekly for 6 months, in preventing relapse of non-A, non-B/C hepatitis in remission after treatment with alpha interferon given thrice weekly according to the following dose schedule: 3 megaunits for 3 months, 2 megaunits for 2 months and 1 megaunit for 1 month. Fifty-three patients with hepatitis C in remission were randomly allocated to a treatment group (n = 26) or a control group (n = 27). A relapse (aminotransferase activity > 1.5 times the upper limit of normal) occurred in 46% of the controls and 35% of the treated patients (NS). Maintenance treatment had no significant influence on histopathologic changes evaluated by three independent observers: in both groups the overall score for histologic lesions improved between the initiation of interferon therapy and the end of the study. We conclude that relapses in patients with non-A, non-B/C hepatitis in remission after treatment with alpha interferon at tapering doses are not prevented by maintenance therapy with low-dose alpha interferon. Journal of Hepatology.