Chylous ascites is accumulation of triglyceride rich fluid in peritoneal cavity. Apart from spontaneous causes, the iatrogenic type usually result from retroperitoneal operations. This is a case report of an eleven year old girl, who developed chylous ascites after choledochal cyst excision and roux-en- y hepatico-jejunostomy. The condition discovered in the seventh post-operative day and treated by percutaneous drain, low-fat diet, and octreotide . The condition was resolved after two weeks.