We describe moderate hyperbilirubinemia in a 28-year-old man who suffered from gallstones and splenomegaly, with combined disorders of hereditary spherocytosis (HS) and Gilbert`s syndrome (GS). Since it is difficult to diagnose HS in the absence of signs of anemia, we evaluated both the genetic mutation in the UGT1A1 gene and abnormalities in the erythrocyte membrane protein; the former was heterozygous for a UGT1A1 allele with three mutations and the latter was partially deficient in ankyrin expression. This is the first report of the concomitance of HS and GS with three heterozygous mutations [T-3279G, A (TA)7TAA, and G211A] in the UGT1A1 gene. (Korean J Hepatol 2010;16:321-324)