Crigler Najjar syndrome type II is related to a defect of bilirubin conjugation due to partial deficiency of the enzyme uridine diphosphate-glucuronyl transferase. Usually has a benign course, unlike Crigler Najjar type I, where the enzyme deficiency is total and the affected patients usually die at early ages. We present the case of a teenager with indirect hyperbilirubinemia, seizures and cerebral palsy. A good clinical history with pedigree and appropriate functional tests allowed us to determine the definitive diagnosis. This is an autosomal recessive disorder, has a very low prevalence worldwide, and is a diagnostic challenge for physicians in general.