Long term exposure to loud noise acts as an environmental stressor which affects the physiological as well as the psychological well being of the individual. The aim of the present study is to determine the effect of noise stress on immune system and to compare the acute and chronic stress effects on adult male albino rats. The effect of acute and chronic noise stress on albino rats was studied by estimating total leukocyte count (TLC), differential leukocyte counts (DLC), levels of serum cortisol and immunoglobulins G (IgG). Acute noise stress causes significant decrease in TLC and DLC while, cortisol and IgG serum levels are significantly increased. Chronic noise stress has variable effects on TLC and DLC according to its duration which first increased then after the 4th week become significantly decreased closely related to normal level. Cortisol and IgG serum levels are significantly decreased with increasing stress duration. In conclusion, the acute and chronic exposure to noise acts as a stressors affecting immune system which become adapted with increasing stress duration. therefore, it is supposed that homes and places of working must be build far away of noisy of factories and other places with noise.