A subgroup of patients with steroid-responsive minimal change nephrotic syndrome (MCNS) is classified as steroid-dependent because of repeated relapses of proteinuria during prednisone taper, or within four weeks of withdrawal of prednisone. The long-term outcome of this subgroup of patients has not been documented. Thirteen patients with onset of steroid-dependent MCNS (biopsy-proven) in childhood have been followed for 10-22 years (mean 15.6 years); 8 patients have been in stable remission for 2-13 years (mean 5.5 years); 3 remain steroid-dependent 12, 18 and 22 years after onset; and 2 had steroid-responsive relapses after 5 and 8 years of remission. In 3 patients steroid-dependent MCNS remitted without cytotoxic therapy 7-11 years after onset. Cyclophosphamide was administered to the remaining 10 patients: 8 had prolonged remissions (1.1-13 years, mean 4.3 years) and 2 relapsed shortly after cyclophosphamide therapy. Of the 8 patients who had prolonged remissions after cyclophosphamide, 3 have had no relapses 5-13 years after therapy. In 5 of these 8 patients steroid-dependency recurred 1.1-3 years after cyclophosphamide and a second course was given, resulting in remissions of 1.4-8 years in 3 patients, change to a frequently relapsing pattern in 1 patient and remission of 3 months in one patient who then became steroid-dependent again. We conclude that the long-term outcome of steroid-dependent MCNS is favorable. Cyclophosphamide is useful in the management of these patients and a prolonged course of alternate-day prednisone therapy after cyclophosphamide may be helpful in maintaining remission.