Over exposure to X-ray radiation is detrimental to the living cells and may lead to development of life-threatening diseases. It is intuitive to postulate that a low level exposure may lead to functional abnormalities in human immune cells. Therefore, the objective of the present study was to study the effects of X-ray radiation on the total leukocyte count (TLC) and phagocytic activity of Polymorphonuclear neutrophils (PMN). A group of 42 apparently healthy X-ray technicians were recruited with age ranging from 25-50 years. They were matched with another group of 42 control healthy volunteer subjects in terms of age, sex and ethnic variation. The mean exposure level of X-ray radiation in X-ray technicians was 72.4 mrem per calendar quarter and 289.6 mrem per year. TLC was performed by using a Beckman Coulter counter and phagocytic activity of whole blood and PMN was determined by measuring chemiluminescence (CL) response with a chemiluminescence luminometer. The mean value of CL response was significantly decreased (p<0.0005) in X-ray technicians, even though they had low levels of exposure, compared to their controls. However, no significant difference was observed in TLC between the two groups at this low level of exposure. Exposure to X-ray radiation decreases the physiological functions of PMN as measured by decreasing chemiluminescence response even at low levels of exposure.