Appendicitis (AP) is an inflammation of the appendix that occurs typically when the lumen gets obstructed. If the inflammation persists it will lead to complications such as perforation, collection, and phlegmon. on clinical examination typical acute appendicitis presented with fever, tenderness in the Right iliac fossa. laboratory investigations can aid in diagnosis usually it is presented with leukocytosis and elevated ESR and CRP in cases of complicated appendicitis. serum of bilirubin showed to be increased in some cases so hyperbilirubinemia can be a predictor of the severity of acute AP. In this article review, the aim is to know the association between complicated AP and elevated total and direct bilirubin.