This study is designed to investigate the combined effect of two kinds of commercial probiotic with or without artificial substrate in a periphyton based system on growth performance, feed utilization and chemical body composition on Nile tilapia (Oreochromis niloticus). Twelve thousands nine hundred and sixty (12960) Nile tilapia fingerlings with initial weight (1.86g) were used for 105 days. The experiment was carried out as factorial arrangement (2x3) experimental treatments. Two levels of additional periphyton substrate area (S^0%, S^66.67%) of tank surface were tested where the superscripts refer to artificial substrate levels of 0%, 66.67% of tank area (each of 24 m³) and three supplementation  levels of probiotic (0% without supplementation of probiotic (pro0) and two different commercial probiotic each one supplemented to the basal diet  with the recommended level mentioned by the producer 0.1g/kg for the first (Ecobiol Aqua plus^®) (pro1) ,2g/kg for the second (Biogen^®) (pro2). Each treatment has three replicate of concrete tanks representing 18 concrete tanks (24 m³each, 8m length x3m width x 1m depth). 720 fingerlings were reared in each concrete tank; fish fed basal diet twice a day. The optimum growth performance and feed utilization of Nile tilapia fingerlings were obtained at artificial substrate S^66.67% in periphyton based system with the second probiotic (Biogen^®) suggesting that periphyton should be a part of the diet of fish at commercial and applicable scale.