The immediate infectious pancreato-biliary complications of endoscopic retrograde cholangiopancreatography (ERCP) warranting transfer to a surgical unit are analyzed, in order to evaluate their frequency and severity as well as means of treatment and prevention. Thirty complications of this type were observed in a series of 3226 ERCP performed with or without endoscopic sphincterotomy (ES) over a six year period (0.9%). ES had been performed in 12 of 30 cases, but the complication could not be attributed to the procedure. Post-ERCP complications included: acute cholangitis: 16 cases (53%); acute cholecystitis: 8 cases (26%); acute pancreatitis: 4 cases (13%); infected pancreatic pseudocyst: 2 cases (6%). The global mortality rate was 16.6% (five patients): Four of the deaths were due to septic complications. Twenty-seven of the 30 patients underwent surgery, and three of them died (11%). Acute cholangitis was responsible for most of the deaths (four of five) and the mortality appeared related to the long interval before surgery (three of four deaths). Strict adherence to good endoscopic procedures (aseptic conditions, injection without excessive pressure, antibiotic prophylaxis) and decompression of the biliary tract (nasobiliary drain or transhepatic catheter) should help reduce the frequency of post-ERCP complications, and especially cholangitis, which appears to benefit from early surgical treatment.