The effect of dietary protein levels (35%, 40% and 45%) on growth, survival, feed utilization and body composition of mono sex and mixed sex of Nile tilapia; Oreochromis niloticus L. fry was investigated. Fish were fed frequently to satiation for 7 days a week for 56 days. Results showed that fish growth was significantly affected by protein level. The highest growth performance of fry were obtained with 45% protein diet and the poorest one was obtained with 35% protein diet in both mono and mixed sex Nile tilapia, Oreochromis niloticus fry. Mono sex tilapia were  reared in hap in earthen pond showed the highest weight gain, specific growth rate, feed conversion ratio, feed efficiency and protein efficiency ratio, while mixed-sex tilapia showed the lowest weight gain, specific growth rate, feed conversion ratio, feed efficiency and protein efficiency ratio. In conclusion, it was found that 45% crude protein had the highest growth performance parameters, feed utilization and economical evaluation for mono sex Nile tilapia (O. niloticus) fry under this experimental condition.