During the years 1984-1992, 74 patients of mean age 45 (range 6-71) years with chronic pancreatic pseudocyst were treated by percutaneous cystogastrostomy. They comprised 45 men and 29 women. A diagnosis of chronic pancreatitis was verified in 55 patients (74 per cent); pain was the indication for treatment in all cases. The catheter was successfully placed at the first attempt in 68 patients (92 per cent). Immediate complications occurred in four patients (5 per cent); there have been none since 1986. Abscess formation was seen in eight patients (11 per cent). One patient died 4 days after the procedure from myocardial infarction giving a mortality rate of 1 per cent; no death has occurred since 1986. The mean observation time was 27 (range 0-108) months. Pain disappeared or decreased in almost 90 per cent of patients and weight gain was seen in 80 per cent. The method described is less traumatic than operation, and mortality and complication rates compare favourably with those seen after surgery; the results are at least as good.