Abstract: This study was undertaken to evaluate the effect of dietary supplementation with Vitamin E (VE) and stocking density on growth performance and histological responses of broiler chicks. Cobb-500 3 day old chicks were randomly distributed to eight equal groups, each of which contained four replications. An experiment with a factorial arrangement of treatments (4x2), 4 levels of VE (0.0, 200, 300 and 400 mg kg-1 diet) and 2 levels of stocking density (11.9 birds m-2 as the normal stocking density or 16.66 birds m-2 as the high stocking density). Apart from the effect of stocking density, dietary supplementation with VE did not affect Live Body Weight (LBW), Body Weight gain (BW), Feed Intake (FI), Feed Conversion Ratio (FCR), carcass traits or lymphoid organs examined. The high stocking density had a negative effect on LBW, BWG and FI but FCR and carcass traits were not affected compared with the normal stocking density, irrespective of the effect of added VE. Dietary supplementation with VE enhanced the activity of spleen, bursa and thymus to produce many lymphocytes that help improving the immunity of birds. The high stocking density, applied herein, exerted a negative effect on the histology of lymphoid organs which may cause low immune responses. The results of the present study shown that supplemental dietary VE could improve the histological responses of lymphoid organs in broiler chickens.