Between 1966 and 1980, 54 patients (40 men and 14 women) with a mean age of 38 years were operated on for a pancreatic pseudocyst at the Department of General Surgery, University of Göttingen. The aetiology of the cysts was alcohol abuse in 35 patients, biliary diseases in 8, blunt abdominal trauma in 4, virus-induced in 2 and unknown in 5. With the exception of those who had had trauma, all patients were suffering from chronic pancreatitis. Surgical therapy included in all cases a cystojejunostomy (52 with a Roux-Y-limb and 2 with an omega loop). The mean follow-up period was 13 years (range 6 to 20 years). The late mortality was 15 per cent (8 of 52 patients). Recurrent cysts occurred in two patients (5 per cent) and relapse of pancreatitis in one third of the patients. Deterioration of carbohydrate metabolism was observed in 20 per cent of the patients. After drainage operation stool fat content became normal in 20 per cent and deteriorated in 13 per cent. Persistence or cessation of alcohol intake influenced the long-term results. From these data we conclude that both alcohol withdrawal and sufficient drainage of the pseudocyst are important factors in the prognosis of pseudocyst.