Introduction: This study is the fi rst study about the distribution ABO blood types at children with acute leukemia in Federation of Bosnia and Herzegovina. The aim of the study is to point out distribution of blood type groups at children with acute leukemia (AL) Methods: The number of children in this study was the following: 145 children with acute leukemia and 27 of children with acute myeloblastic leukemia (AML). All of the children were treated at Hemato- Oncology Unit of Pediatric Clinic in Sarajevo, in the period January 2000 until December 2010. Age of children was between 1 month and 15 years. Results: The results showed that different blood types were registered in 93. 1% of children who got ill and treated from acute leukemia for the mentioned period. At 6. 9 % of children, none of the blood types were registered. It was noticed that 40.9 % children who have registered blood type O, 37% blood type A,16% blood type B and 6.5% blood type AB had AL, too. It has been observed that children with following blood types had AML: O, 47.8%, A, 47.7% and AB, 30.4%. Conclusion: Signifi cance ABO types distribution was confi rmed for children with ALL, p<0, 05. The analysis of the distribution of ABO types based on gender showed that signifi cance was confi rmed at females with both ALL and AML (p<0.05).