Abstract : Abstract—Health monitoring of radiation workers due to radiation exposure can be done by examination of the hematopoietic system, especially white blood cells which are very sensitive to radiation exposure and can be used as an indicator of body damage. The purpose of this study was to determine the differences in the biological effects of ionizing radiation on the hematopoietic system of radiation workers and non-radiation workers as controls. A total of 3 mL of blood from 57 people (34 radiation workers and 23 subjects as a control) were taken using a syringe and then put into an EDTA tube and shaken slowly to avoid clotting. The blood was examined using the ABX Micros 60 hemoanalyzer instrument with standard procedure in the PTKMR Laboratory. An independent sample T-test was used to determine the significant differences between radiation workers and controls. Pearson chi-square test was used to evaluate the significance of each parameter through p-value (p<0.05). The results showed that the numbers of hemoglobin, erythrocytes, leukocytes, platelets, hematocrits, MCV, MCH, MCHC, RDW, MPV, PDW, lymphocyte, monocytes, granulocytes, % lymphocytes, % monocytes, % granulocytes of radiation workers did not decrease and still within normal limit. The results of the statistical test did not show a significant difference between radiation workers and controls (p> 0.05). It was concluded that radiation workers did not have any impact due to work with radiation.