Effect of alpha-tocopherol (vitamin E) on growth of juvenile giant tiger prawn Penaeus monodon Fabricius (average weight 15 g) was studied using RBD for experimental design. Shrimps of each sex were reared separately. Shrimps were fed artificial diet supplemented with dl-alpha-tocopherol acetate form (0, 150, 500 and 2500 mg/kg diet). Shrimps were reared at density of 30 individuals per pond and reared for 8 weeks. Feeding regime was five times at 06.00, 10.00, 14.00, 18.00 and 22.00 hr. Level of alpha-tocopherol and sex exhibited no effects on survival rate, molting period frequency, %, ash, % organic, and % water content in the shrimp muscle (P<0.05). Level of alpha-tocopherol also showed no effects on growth, but affected % protein, % total lipid and hepatopancreas weight. Hepatopancreas weight of shrimp decreased as level of alpha-tocopherol in diet increased. Sex exhibited effect on weight significantly. Female was larger than male (P<0.05), but had lower protein. Total lipid and hepatopancreas weightshowed no difference between sexes