Patients with hemophilia and thalassemia are two groups of hereditary disorders that, periodically, use blood and blood substances. The aims of the present study are determination of the frequencies of different types of coagulation disorders, and a comparison of the frequencies of ABO & Rh phenotypes among affected individuals with the control group (blood donors).

          The subject group were all affected persons were referred to hemophilia and thalassemia centers in Hamadan. Primary information was collected from their files, then were classified and analyzed. The control group were blood donors that were registered in Hamadan blood bank.

          Results showed that the different types of coagulation disorders in affected individuals referred to the Hemophilia and thalassemia centers during 1998 were Hemophilia A (61.96%), Hemophilia B (20.86%), Von Willbrand (5.52%), Platelet deficiency (4.91%), Factor XIII deficiency (3.68%) and Factor VII deficiency (3.07%).

          In general, results showed that in population with Hemophilia A, frequencies of A and O blood types were statistically different with the blood donors. The lowest rate of negative Rh, was in the population with thalassemia. The sex ratio of the affected persons was also different with control group.