Introduction: Hemiscorpius lepturus scorpion present in the southern provinces of the country, especially in Khoozestan stings a lot of people that results in long-standing dangerous side effects and sometimes even mortality. As the study of the effects of this scorpion venom on some laboratory animals can determine its mechanism of action and help us to cure people stung by scorpions, this study has been done to study the effects of Hemiscorpius lepturus venom on levels of WBC, RBC and hematocrit of rats. Methods: An experimental study has been done on 51 rats of the same race with approximate age of 2-3 months, and weight of 200-250 grams. . All the hematological features including WBC (White Blood Cell), RBC (Red Blood Cell) and HT (Hematocrit) were measured prior to venom injection. The same procedures were followed after injection of 1 microlitre of venom. Results before and after injection have been analyzed by Wilcoxon Matched, Pairs signed and Ranks statistical tests. Results: The results of the study have shown that the venom caused changes in the levels of WBC, RBC and Hematocrit. The mean level of WBC at the start was 10234, whereas following the venom injection it reached to the level of 11757( P<0.0007). The mean number for RBC before the treatment was 7509130 and after injection, the number declined to 7065098( P<0.0001). The average amount of Hematocrit before and after injection was 40.087% and 39.0588 %, respectively (P<0.001). Conclusion: Hemiscorpius lepturus venom has some effects on the levels of WBC, RBC and hematocrit of rats. The study of the hematological changes in humans can lead to better study of the effect of this venom and consequently suitable cure for the injured