The aims of the present study were to assess the effects of the replacement  graded levels of aquafat-O^® (0, 1, 2 and 3%) instead of corn oil on the growth performance, feed and nutrients utilization, chemical composition of the whole fish body and the economic efficiency of adult Nile tilapia Oreochromis niloticus,( females and the males) for 11 weeks. The obtained results showed  the  replacement  of aquafat-O^®  at   a level of 1% for adult O. niloticus, females and  males significantly (P ≤ 0.05) enhanced fish growth, feed intake and nutrients utilization, as well as realized slight improving of chemical composition of the whole fish body and economic efficiency. Hence, it could be concluded that  replacement  of  aquafat-O^® at a level 1% of  corn oil  led to improvement of productive performance and economic efficiency of  the  adult females and males Nile tilapia (O. niloticus).  It so  may  be using of aquafat-O^® as  a  growth promoter in fish farming and hatcheries.