A nutrition diet experiments were conducted to investigate the effects of dietary of supplemental brown seaweed meal on growth performance of male, female, and mixed-sex group of Nile tilapia, Oreochromis niloticus. Three different iso-proteinous (CP 32%) diets containing 0% (BSM 0), 4% (BSM 4), and 8% (BSM 8) level of brown seaweed meal were prepared and fed to replicate trials of individual males, individual females, and mixed sex tilapia.Male Nile tilapia groups also showed the best result of WG, FE, SGR, PER, and NPU came from fish fed by BSM 8. In case of experimental groups BSM 4, the results were significantly (p<0.05) greater than fish in BSM 0 but not different with fish in BSM 8 from Male and Mixed-sex group of rearing condition. In female Nile tilapia group, the result of WG, FE, SGR, PER, and NPU were not significantly (p>0.05) different within levels of feeding trial with range 1.07-1.52%/day and 60.40-89.46%, respectively. Nevertheless, the highest results of SGR and FE also were observed in BSM 8. Based on the result, BSM could be added in a fish diet up to 8%, and male tilapia are greater than female for production pupose.