The clinical features and long-term outcome of 91 cases of adult-onset PSGN in Hong Kong were reported. There were 46 male and 45 female with age ranging from 13 to 56 yrs (mean 18.6). The diagnosis was based on clinical manifestations and renal biopsy was performed in 29 cases. The main manifestations were acute nephritic syndrome (72.5%) and acute nephritic-nephrotic syndrome (27.5%). Serum creatinine was increased in 48.4% of the patients at presentation. Four cases presented with acute renal failure. Serial serum C3 levels were determined in 48 patients. It was decreased in all patients at presentation but returned to normal within 15 weeks. The follow-up duration of this series ranged from I to 19 yrs (mean 4.73 yr) 67.03% recovered early (within 3 mts); 14.29% recovered later (from 6 mts to 7 yrs): 16.48% had persistent or intermittent proteinuria and or haematuria. Two cases developed chronic renal insufficiency. Our results suggested that the prognosis of PSGN in adults is relatively good and the indications for renal biopsy in adult-onset PSGN were discussed.