Hemolytic disease of the fetus and newborn (HDFN) also called as "erythroblastosis fetalis" is characterized by the increased rate of red blood cells (RBCs) destruction. Hemolysis should always be investigated even if the anemia is mild and apparently trivial. The principle clues which suggest hemolytic anemia includes: increased number of reticulocytes and/or circulating nucleated RBCs, unconjugated hyperbilirubinemia, a positive direct antiglobulin test and characteristic changes in red cells in the blood films. Based on etiology, hemolysis in newborn can be immune or non-immune mediated. The immune-mediated hemolysis due to blood group incompatibility between the mother and the fetus is the main cause of HDFN.