Long term outcome of 124 Thai adult nephrotic patients was determined. Nephrotic syndrome affects the young more often than the old (median age 29 years). The most common pathology was IgM nephropathy (45.2%), membranous nephropathy (31.5%) and FSGS (23.4%). Sixty-four per cent of patients with IgM nephropathy respond to corticosteroid within 4-8 weeks while twenty three per cent were late responders. However, more than half of these patients were relapsers or steroid dependent. Response to corticosteroid occurred in 48.2 per cent of patients with FSGS while the response rate of patients with membranous nephropathy was only 23.1 per cent. Survival analysis revealed that five and ten years renal survival of IgM nephropathy was 98 per cent. Five and ten years renal survival of FSGS was 83.7 per cent and 76.8 per cent while those of membranous nephropathy was 95 per cent and 63.3 per cent. The response to corticosteroid was associated with better prognosis in FSGS. Our results show that patients with IgM nephropathy and membranous nephropathy have a generally good prognosis. Renal function is usually well preserved for at least ten years. The prognosis of patients with FSGS varied and correlated with the degree of steroid responsiveness.