Hereditary spherocytosis is the most frequent congenital hemolytic anemia and is characterized with variable degree of anemia, jaundice, and splenomegaly. In the case of severe hyperbilirubinemia out of proportion with hemolysis, other causes of hyperbilirubinemia must be considered. Gilbert syndrome (GS) is an autosomal dominant disorder characterized with intermittent hyperbilirubinemia without any other sign and symptom of liver disease as a result of reduced activity of uridine diphosphate-glucuronyl transferase 1A1. The calculated rate of coexistence of these 2 diseases is 15 to 35/million births. Here we present a 21-month-old girl with hereditary spherocytosis diagnosed at the age of 40 days with hyperbilirubinemia out of proportion of hemolysis which led to diagnosis of GS. Thereby, the diagnosis of GS should be considered in unexplained unconjugated hyperbilirubinemia in different age groups, including infants and toddlers.