Hemoglobinopathy and allied hemolytic disorders are important genetic and public health problems in Orissa. These cause high degree of hemolytic anemia, morbidity and mortality in the vulnerable populations. A total of 465 Ashram School children aged 6-15 years belonging to Bathudi, Bhumiz, Kolha and Santal tribes in six localities of Mayurbhanj district of Orissa were screened for hemoglobinopathy, glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, ABO and Rhesus blood groups serology and any other hereditary condition. The sickle cell trait (Hb AS) was detected in Santal (1.0%), Bathudi (1.0%) and Bhumiz (0.9%) tribals. No case of homozygous sickle cell disease was detected among the tribes of Mayurbhanj district. The beta-thalassemia trait was detected in Santal (8.0%), Kolha (2.0%), Bhumiz (1.7%) and other tribal (3.8%) students. Sickle cell hemoglobinopathy and beta-thalassemia are prevalent in this district among the tribes, but the frequency is very low. The prevalence of G-6-PD deficiency is considerably high (7.7-9.8%) among the tribes of Mayurbhanj district in Orissa. Out of total 43 G-6-PD deficient subjects, there were 32 males, 9 heterozygote females and 2 homozygous females. This shows that the antimalarial drugs should be administered with caution as these cause hemolytic anemia, sometimes fatal also. The distribution of ABO and Rhesus blood groups shows the preponderance of B blood group (33.8%) over O (29.6%) and 2.1% cases of Rhesus negativity were detected among the Bathudi tribe. This pattern is consistent with the characteristic features of tribal populations in India.