Abstract. The objective of present study was to determine effect of feeding tilapia fishes (Oreochromis niloticus) with the commercial diets partially substituted by Organic Pelet Feed (OPF) composed by cattle feces, soybean meal, rice bran, and probiotic on total income. The study was conducted in Research Station II Ie Sueum, Syiah Kuala University, June 1 until August 29, 2016. The study used 1600 of a week old of tilapia fish. The study was performed into completely randomized design (CRD) consisting of 4 treatments and 4 replications. Each replication was an experimental unit, consisting of 100 fishes. The treatment tested was feeding tilapia fishes with commercial diets partially substituted by OPF with the level of 0, 10, 20, and 30%, respectively. The OPF was made up of cattle feces 50%+rice bran 30%+soybean meal 19%+probiotic 1%. Parameters measured were final body weight (FBW), total feed consumption (TFC), and Income Over Feed Cost (IOFC) as well as total income. The data of FBW and TFC were analyzed by Analysis of Variance (ANOVA) (Ott, 1993), while the data of IOFC and total income were analyzed by the economical parameters of R/C and B/C ratio (Soekartawi, 1995). The results of study showed that OPF could be used up to 20% to substitute commercial diet in raising tilapia fish with the best level was 10% most significantly (P