A patient with combined deficiency of erythrocyte glucose phosphate isomerase (GPI) and glucose-6-phosphate dehydrogenase (G6PD) is presented. The propositus has persistent unconjugated hyperbilirubinemia. One of his two brothers exhibits the same rare enzymatic defect, but without any clinical symptoms. The electrophoretic pattern of GPI showed GPI type 1. There seems to be a correlation between the unconjugated hyperbilirubinemia and the combined enzymopathy in our patient.