The potential combination of soybean with Cnidoscolus chayamansa (Chaya) leaf to produce a composed feed in Nile Tilapia culture has received proportional little research. Furthermore, soybean is used to make meals for humans as well as for livestock. Currently, the cost of soybean meal keeps increasing due to high demand both as food for humans as well as for livestock feed. The aim of this research was to evaluate the growth performance of Oreochromis niloticus (Nile Tilapia) fingerlings placed on partial replacement of soybean meal with Chaya leaf meal. Feed Conversion Ratio, Protein Efficiency Ratio and Nitrogen Metabolism were used to obtain the best nutrient utilization. From this work, it has been established that Chaya leaf meal is a good source of protein. Moreover, it gave good result for the growth and nutrients utilization thereby transforming to cost minimization and profit maximization of Nile Tilapia. This book contributes knowledge and provides useful information on soybean/Chaya leaf fish feed to fish farmers, feed producers and fisheries scientists.