One hundred and ninety-three nephrotic children with a total of 271 admissions during the past decade, from 1980 to 1989, were retrospectively reviewed for acute complications and unusual features of nephrotic syndrome. One hundred and forty-nine patients were male, 44 female. Hypertension was found in 41 children (21.2%). Nine patients (4.7%) had a total of 11 episodes of hypovolemic shock. These shock patients had a more severe hemoconcentration (mean hemoglobin concentration 19.6 +/- 1.5 g/dl) and hyponatremia (mean serum sodium 127.5 +/- 8.5 mmole/L). Bacterial infections occurred in 28 children (14.5%) with primary peritonitis in 13, sepsis in 6, cellulitis in 4, urinary tract infection in 4 and osteomyelitis in 1. Almost all infections were caused by gram-negative bacilli. Other complications or features included tetany in 4 (2.1%), thromboembolism in 2 (1.0%), pancreatitis in one (0.5%) and Fanconi syndrome in one (0.5%).