The purpose of this prospective study was to determine the clinicopathological significance of necrotic areas demonstrated by rapid-bolus contrast-enhanced computed tomography (CT) in patients with biochemically predicted severe pancreatitis. Although CT necrosis occurred significantly more frequently in patients with clinically severe (ten of 12) compared with mild (seven of 20) pancreatitis (P less than 0.025), seven of 17 (41 per cent) patients with CT necrosis developed clinically mild pancreatitis and six of ten (60 per cent) patients with clinically severe pancreatitis and CT necrosis recovered with conservative management. The site and extent of CT necrosis did not correlate with disease severity. Fine-needle aspiration cytology, operative and post-mortem findings and endoscopic retrograde cholangiopancreatography examinations all strongly suggested that CT necrosis represents true pancreatic necrosis. We conclude that the finding of CT necrosis is not in itself an indication for operative intervention, but that rapid-bolus contrast-enhanced dynamic CT greatly facilitates the planning and execution of surgical therapy.