Chylous ascites is a rare clinical manifestation characterized by ascitic chylomicrons resulting from mechanical obstruction of or leakage from the lymphatic channel. Chronic disorders, especially malignancies, account for most cases of chylous ascites. Acute chylous ascites is less common than the chronic form. We present a rare case of acute chylous ascites secondary to acute pancreatitis during the third trimester of pregnancy. This 24-year-old woman was referred to our emergency department because of severe epigastralgia for several days. Abdominal computed tomography revealed diffuse enlargement of the pancreas and peripancreatic exudation. Massive chylous ascites was found during emergent abdominal exploratory laparotomy. An emergent cesarean section was done because of fetal distress and there was no further accumulation of chyle. A pancreaticocutaneous fistula resulting from the cesarean section was treated successfully with a fistulectomy. In conclusion, chylous ascites is a rare complication of acute pancreatitis. Cesarean section may be helpful in terminating chylous accumulation in acute pancreatitis during the third trimester of pregnancy.