Nineteen pancreatic fistulas were treated with somatostatin (ST) and total parenteral nutrition (TPN). Five of the fistulas developed in an uninflamed pancreas, whereas 14 fistulas developed secondary to a necrotizing or chronic pancreatitis. Fistular output varied between 20 and 800 ml/day (median, 160 ml) during TPN before ST treatment; amylase concentration was 10,500-800,000 UI/l. Twelve of 16 (75%) fistulas were contaminated with bacteria. Thirteen of 19 (68%) fistulas closed after a median treatment of 7 (range, 2-14) days. Seven of eight fistulas with open drainage to the bowel healed, whereas only one of six with obstructed drainage closed. All of the uninfected fistulas and half of the infected fistulas closed. The findings suggest that somatostatin treatment speeds up the closure of pancreatic fistulas with open drainage to the bowel but is not beneficial when the intestinal drainage of the fistular region to the bowel is obstructed.