Introduction: An apparent re-emergence of kernicterus has been recently reported, with some cases occurring in otherwise healthy breastfed newborn. Methods: We describe a case of kernicterus in a term Caucasian newborn. Results: An exceptional polymorphism of UGT1A1 gene promoter co-existed with asymptomatic inherited spherocytosis, due to erythroid anion exchange (band-3) deficiency. Both concurred to the development of severe neonatal hyperbilirubinaemia. Conclusion: As some cases of kernikterus remain unresolved, haemolytic diseases and bilirubin metabolism disorders should be carefully investigated in unexplained severe neonatal hyperbilirubinaemia.