The present project was designed to study the prevalence of ABO blood groups in Leukemia patients. For this purpose, 260 blood samples of leukemia patients were collected from April 2011- July 2011 and their blood groups were determined by a simple and widely used method blood typing using Anti-A serum, Anti-B serum and Anti-D serum. It was noted that out of 260 samples taken, 154 were taken from male and 106 were taken from females who had leukemia. The percentage of male and female was 59.2% and 40.8% respectively. The prevalence of types of leukemia was also noted. Out of 260 patients, 248 had Acute Lymphoblastic Leukemia (ALL) and 12 were having Acute Myelogenous Luekemia (AML). The percentage for Acute Lymphoblastic Leukemia was 95.4% and %age for Acute Myelogenous Leukemia was 4.6%. The number of patients with blood groups A, B, AB, and O was 67, 90, 41 and 62 respectively. The highest prevalence was noted in blood group B i.e. 34.6% followed by blood group A 25.8%, then O 23.8% and AB 15.8%. The prevalence of Rh positive among leukemia patients was found to be 96.1% i.e. out of 260 patients 250 were Rh positive and prevalence of Rh negative was 3.9% i.e. 10 patients.