Biliary atresia associated with positive cytomegalovirus IgM results is a rare condition characterized by pro-gressive inflammatory obliteration of the intra-or extrahepatic ducts. It is caused by a perinatal autoimmune reaction against cytomegalovirus (CMV). Diagnosis is made based on positive IgM for CMV and liver biopsy with evidence of bile duct atresia. Knowledge and timely identification of this disease leads to early surgical management, considerably improving the prognosis of these patients. This is the clinical case of an 82-day-old female patient with late-onset acholia, choluria, and jaundice, associated with conjugated hyperbilirubinemia, elevated liver function tests and positive CMV IgM results. Intraoperative cholangioresonance confirmed bile duct atresia. The Kasai procedure was performed, and a liver biopsy was taken, confirming the diagnosis.