Congenital cystic dilatations of the bile duct are rare malformations representing 1 per 13,000 births with a female predominance. Diagnosis of this pathology is based on radiological imaging especially radiological investigations conducted on an ultrasound coupled with Computed tomography (CT) scan and especially a bili-MRI which allows the analysis of the bile duct malformations and the anomalies of the pancreaticobiliary junction. We will discuss in this clinical case the various radiological aspects of cystic dilatations of the biliary duct.