It is quite common to see abnormal peritoneal folds in the abdominal cavity. Some of them might compress or strangulate the viscera and others might determine the direction of the flow of peritoneal fluid, pus or blood. Many unusual clinically important peritoneal folds such as Ladd's band, cysto-gastro-colic fold, omento-cystic fold, and cysto-colic fold have been reported earlier. Knowledge of these folds is important for radiologists, gastroenterologists, and surgeons. We report an unusual cysto-duodeno-colic fold observed during our dissection classes. The fold was seen to compress the duodenum and colon. The fold extended from the descending part of the duodenum and the transverse colon to the gallbladder. It enclosed the entire gallbladder. A case similar to this has not been reported yet. It is important for the gastroenterologists and laparoscopic surgeons to be aware of this fold to avoid misdiagnosis and iatrogenic injuries.