From 1981 to 1987, 40 patients with severe acute pancreatitis were operated on using a direct retroperitoneal approach, 22 primarily and 18 after a first operation performed through another incision. The severity of the disease was assessed by Ranson's bioclinical and computed tomography scan scoring systems. The retroperitoneal approach consisted of a left lateral incision, just anterior to the 12th rib, allowing direct access to the pancreas and a complete manual exploration of the gland and peripancreatic spaces. All patients but one were operated on for infected necrosis. The overall mortality rate was 33 per cent but was lower in the patients operated on primarily through a direct retroperitoneal approach (18.2 per cent). Twenty patients (50 per cent) developed a local complication (haemorrhage, colon fistula and/or necrosis). The direct retroperitoneal approach permits the removal of necrosis and several reoperations without the risk of large wound dehiscence and does not preclude the extension of the incision to a subcostal incision when necessary.