Day-old broiler birds (n = 96) were randomly divided into four groups, each group with four replicates and having 6 birds in each replicate. The birds were supplemented with corn-based diet. On day 35, birds were slaughtered to determine the relative weights of heart, liver, kidneys, spleen, gizzard and intestines. Results showed that supplementation of phytase enzymes affected the weight and length of small intestine and feed conversion ratio (FCR) and did not affect the other zoo technical variables like body weight, feed consumption, and weight gain during the whole experimental period. Application of phytasefailed to exert any influence on the weights of gizzard, provetriculus, heart, liver, spleen and empty intestine. The weights and lengths of the small intestine were highly significant (P > 0.05) in the treatment groups. This study showed the potency of phytase to enhance the growth performance in broilers and it will lay foundation for future research on poultry feed in Pakistan.