Aim: The aim of the present study is to report our clinical experiences with MMF in problematic children with chronic glomerulonephritis resistant to corticosteroids and/or other immunosuppressive drugs. Patients and methods: Ten patients with chronic glomerulonephritis resistant to treatment with corticosteroids and other immuno suppressive drugs were treated with mycophenolate mofetil (MMF). Causes of chronic glomerulonephritis were mesangial proliferative glomerulonephritis (4), membranoproliferative glomerulonephritis (3), chronic sclerosing glomerulonephritis (1), focal segmental glomerulosclerosis (1), diffuse endo- and extracapillary proliferative glomerulonephritis (1). MMF 15 mg/kg was used in combination with low-dose corticosteroids and angiotensin-converting enzyme inhibitors. Results: During 24 weeks of MMF therapy, no significant changes were detected in mean serum creatinine, albumin and proteinuria. Severe leukopenia was seen in 1 patient. Additional adverse effects, including nausea and diarrhea, were observed in another patient when the dosage was increased to 20 mg/kg per day. During MMF treatment proteinuria decreased slightly without remission in 6 of 10 patients. Conclusion: Further data and clinical trials are needed to evaluate the possible role of MMF in the treatment of chronic glomerulonephritis of similar etiologies in pediatric patients.