The determination of cell population, immune responses (cell and humoral mediated), FCR, overall mortality, weight of lymphoid organs etc. are good indicators of any stress conditions which may affect the broiler performance.From the findings of this research study,it was concluded that the stress factors like temperature, stocking density,feed deprivation,water restriction and light have adverse effects on the humoral and cellular immune responses of the birds.The stressed birds possessing low antibody titers are more vulnerable to challenge with the virulent strain of NDV virus birds.These stress factors did not have any effect on the overall hematology of the bird except the hetrophil/lymphocytes ratios. Moreover, the stressed birds have lesser functional lymphoid organs compared to non-stressed chickesns.Anti-stressor including Vitamin C, Vitamin E and Glucose showed positive effect on stressed birds body weight and FCR.Recommended floor space, light, temperature, Feed and Water should be provided to the broiler chicks,in view of increased cost of production in Pakistan.