Acute pancreatitis in patients on CAPD treatment is an infrequent, but serious complication. We studied the records of all CAPD patients with acute pancreatitis in the Netherlands from 1979 until May 1992. The incidence of acute pancreatitis during CAPD treatment was 0.46 per 100 treatment-years. In all patients at least one risk factor was present. Hypercalcaemia was the most frequently observed risk factor in our patients. The clinical picture consisted of abdominal pain and vomiting, with normal temperature and normal peristalsis. Plasma amylase was elevated in 18 episodes. Dialysate amylase concentrations exceeded 100 U/l in seven of ten episodes. The dialyate could either be clear, haemorrhagic, or cloudy. Positive dialysate cultures were found in five patients, in most cases with skin flora. No direct correlation with the pancreatitis could be established. Mortality was 58%. Continuation of CAPD or transfer to haemo-dialysis had no apparent effect on the outcome, but the best prognosis was found in patients with a persistently clear dialysate.