Background/Aims: Focal segmental glomerulosclerosis (FSGS) is a common type of glomerular disease that can lead to chronic renal failure. Various therapeutic regimens have been used in nephrotic FSGS patients. The effect of treatment with prednisolone alone or its combination with azathioprine and cyclosporin and parameters related to a poor outcome are studied. Methods: Fifty-one patients with idiopathic FSGS and a follow-up period of 5 years were included. Twenty-five were treated with prednisolone alone (1 mg/kg BW/day) or combination of prednisolone (0.5 mg/kg BW/day) with azathioprine (2 mg/kg BW/day) or cyclosporine (3 mg/kg BW/day) in gradually reduced doses whereas 26 patients received no immunosuppressive drugs. Lower prednisolone dose regimens were used as initial treatment in obese, borderline diabetics or patients with bone disease. The clinical course was estimated using the end-points of 50% or doubling of baseline serum creatinine and/or end-stage renal failure. The contribution of clinical and histological parameters in the clinical outcome was estimated by univariate and multivariate analyses. Results: Increase of baseline serum creatinine by 50% during the follow-up period was observed in 2 treated and 9 untreated patients (8% vs. 35%, p = 0.03) whereas doubling of serum creatinine in 2 and 5 patients respectively (8% vs. 19%, p = NS). End-stage renal failure developed in 4 of 51 patients (8%), 2 treated and 2 untreated (p = NS). Parameters related to a poor outcome were baseline serum creatinine and severity of glomerulosclerosis (multivariate analysis OR = 1.08, p = 0.01). Most of patients (68%) who reached end-points had persistent nephrotic syndrome during the follow-up. Remission of nephrotic syndrome was observed more frequently among treated (75 vs. 30.7%, p = 0.05). Prednisolone alone was followed by remission of nephrotic syndrome in 62.5% whereas combination of lower prednisolone dose with azathioprine and cyclosporin in 80 and 85.7% of patients. No serious side-effects were observed. Conclusion: This and previous studies suggest that steroid and/or immunosuppressive therapy have a role in amelioration of the clinical course and remission of nephrotic syndrome in patients with FSGS A combination of low predisolone dose with cyclosporine could be used as initial treatment in patients with higher risk for side-effects from the usual prednisolone dose.