The effect of low gamma radiation doses (11.883 μGy) on the hematological parameters of several groups of male Blab/C mice was investigated. Twenty-nine animals were divided into six groups (6 mice in each group). The first group was the control group (unirradiated). The other groups were irradiated with a Cs-137 (100μci) gamma-ray source. The irradiated groups were categorized by exposure time (6, 12, 18, 24, and 32 days). At the end of the exposure period for each group, blood samples were collected for analysis. The obtained results indicated that by increasing the exposure time, significant (p≤0.05) decreases in the white blood cells (WBCs), hematocrit (Hct), eosinophils (Eso), and mean corpuscular hemoglobin concentration (MCHC) were detected. Equally, dramatic increases in monocytes (Mono) (P