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Abstract Background and objectives: Nowadays, hematologic disorders are leading health problems in our country. This study attempts to help Public heath planners to do prevention measures and to get ready for doing emergency actions in future. Material and Methods: In this retrospective cross- sectional Study, we worked on all biopsy and aspiration of bone marrow cases (N=469) referred to Dansh pathobiology lab in Tehran, Iran (2007). The Smears were reevaluated by two pathologists. The data such as diagnosis, age, and gender were collected and reported. Results: The total number of annual cases are 469 people consisting of 262 male (55.9%) and 207 female (44.1%). The cases who are less than 15 (15.2%) mostly suffer from ALL-L2.The highest rate is related to 15- 50 year group who mostly have CML and AML .the patients who are more than 50 largely suffer from plasma cell myeloma and CLL . Conclusion: In view of the differences observed in the demographic characteristics of hematological disorder In Iran, we strongly recommend a large scale study to public health authorities providing the necessary planning for preventive measures. Key words: Hematologic disorder, epidemiology, prevalence.