Stress is inevitable for poultry even in state of the art facilities available in modern poultry industry. Birds have limited body resources for growth, reproduction as well as to cope with different environmental stressors. So, they seem to be particularly sensitive to different stressors including the environmental ones resulting alteration in their behavior and physiological responses. Present manuscript describes the different types of stressors and their effect on physio-biochemical parameters along with physiological mechanism to cope with stress.