Minor blood group hemolytic disease is extremely rare, since the overall potency of minor blood groups in inducing antibodies is significantly lower when compared with that of Rh (D) antigen. We hereby report a very rare case of severe neonatal anti-E hemolytic disease due to E minor blood group incompatibility. A term newborn born to a 27-year-old, gravida 3, para 3 mother was referred due to a high and increasing serum bilirubin level despite phototherapy on the 4th day of life. On admission physical examination was normal except for the jaundice, and results of the laboratory investigation demonstrated a moderate-to-severe anemia (hemoglobin 7.8 g/dl) and a severe hemolytic hyperbilirubinemia (serum total and indirect bilirubin levels 36 mg/ dl and 32.8 mg/dl, respectively; reticulocyte count 15%; and a positive direct antiglobulin test). As there was no apparent cause of the hemolytic disease such as Rh or ABO incompatibilities, further investigation (a positive indirect antiglobulin test and a positive irregular anti-E antibody in both the patient and mother, and minor blood group antigen profiles in family members compatible with E minor blood group isoimmunization) revealed the presence of anti-E hemolytic disease due to E minor blood group incompatibility. Two exchange transfusions with a 12-hour-interval were performed with minor blood group compatible fresh whole blood, and the patient was discharged in a healthy condition on the 10th postnatal day. If the most common causes of severe neonatal hemolytic disease such as Rh and ABO incompatibilities cannot be demonstrated in a newborn with significant hemolytic hyperbilirubinemia, anti-E hemolytic disease should strongly be considered in differential diagnosis. It should be kept in mind that a very severe from of minor group antibody hemolytic disease characterized by anemia and severe hyperbilirubinemia many exchange transfusions may be encountered during the course of the disease.