The green pigmentation of the teeth is a rare consequence of neonatal hyperbilirubinemia. About 50 cases of green dental discolouration have been registered in literature, most of which affected children with hyperbilirubinemia caused by biliary atresia. Bilirubin can be deposited in multiple tissues. The pigmentation of skin and mucous membranes is caused by the high cell turnover, contrary to mineralized tissues as dentin and enamel where bilirubin is permanently trapped. The severity and duration of jaundice do not directly correlate with dental changes intensity and tooth discolouration. There are additional predisposing risk factors to the eruption of green teeth in later infancy. This article presents a case involving a 3 years old child with green primary teeth who had a history of neonatal cholestasis and a prolonged conjugated hyperbilirubinemia associated to Alagille syndrome.