Spontaneous biliary peritonitis is rare in adults. We herein report a case of spontaneous biliary peritonitis. An 84-year-old man was admitted to our hospital for abdominal pain for 5 days. He developed fever, jaundice, and abdominal rigidity. Computed tomography (CT) revealed massive ascites in the omental bursa and around the liver. The ascites obtained by diagnostic paracentesis was dark yellow-green in color, which implied bile leakage. With a diagnosis of bile peritonitis, the patient underwent emergency exploratory laparotomy. There was massive biliary ascites in the abdominal cavity, especially in the omental bursa. Because exploration failed to demonstrate the perforation site in the gallbladder and biliary duct, we performed abdominal lavage alone. Postoperative endoscopic retrograde cholangiopancreatography showed stones in the common bile duct, and there was no evidence of biliary leakage. Endoscopic retrograde biliary drainage was performed using a plastic stent to reduce the pressure of the common bile duct. After the operation, the patient showed satisfactory recovery and started oral intake on postoperative day 8. However, the patient developed heart failure due to renal dysfunction with nephrotic syndrome at 1 month after the operation. With a diagnosis of rapidly progressive glomerulonephritis due to immune complex, the patient received steroid treatment for nephritis, diuretics, and carperitide for heart failure. Although heart failure and renal dysfunction improved by these treatment, the patients developed toxic epidermal necrolysis which was refractory to intensive treatments including steroid pulse and immunoglobulin, and the patient died 76 days after the operation.