The effect of exogenous corticosteroid therapy on growth was studied in 12 patients with HBSAgnegative chronic aggressive hepatitis. All patients were less than 13 years of age at diagnosis and were free of cirrhosis. The patients' growth records were retrospectively reviewed for incremental growth changes while they were receiving daily prednisone and alternate-day prednisone, as well as for 1 year after the cessation of therapy. These values were compared with age-matched growth velocities in normal children. Daily steroid therapy was associated with a reduction in growth velocity (p < 0.01). There was an acceleration in growth velocity during the period of alternate-day therapy, compared with predicted values (p < 0.03), which persisted during the 1st year after therapy was discontinued (p < 0.02). Nine of 12 patients crossed growth percentiles during steroid therapy. We have confirmed that daily steroid administration is associated with a reduction in linear growth, while alternate-day therapy has an apparent positive effect on growth, presumably through control of the underlying disease. The mechanism of this supranormal growth rate is unclear.