This study was carried out at the Central Laboratory for Aquacul‌ture at Abbassa, Abou-Hammad, Sharkia, Agricultural Research Centre. This experiment aimed to investigate the influence of dietary energy and protein levels (different P/E ratios) with different percentages of fish meal protein to soybean meal protein (FM:SM ratios) on growth perfor‌mance of Nile tilapia, Oreochromis niloticus, fingerlings. The experiment started on 29/3/1995 and lasted for 98 days. Sixteen concrete ponds (each pond had a total area of 24 m2) were kept dried for about one month in order to remove all aquatic weeds. After this period, all ponds were divided into 3 pens (total area 8 m2) representing 3 replicates. All ponds were filled with fresh water for about one week before stocking the fish. Each pond was provided with flow water from Ismailia canal to keep the pond clean and air stones used to keep proper level of aeration in the water. A total of 768 Nile tilapia, Oreochromis niloticus, fingerlings were obtained from Abbassa hatchery. The experimental fish were healthy, free of any parasites and had an average weight 35.50g ± 0.20 with average total length 13.00 cm ± 0.02 at collection time. Tilapia fin‌gerlings were taken randomly and transferred with special care after weighing, and distributed into the experimental sixteen ponds to repre‌sent 16 nutritional treatments (3 replicates for each nutritional treat‌ment). Tilapia were stocked in pond using the optimum stocking rate of tilapia (2 fish/m2) (16 fingerlings per each pen). Two metabolizable energy levels (3000 and 3500 Kcal/Kg diet) and two protein levels (30 and 35%) were used to prepare four protein/ energy ratios (CP/E ratio, mg/Kcal/Kg diet) (100, 110, 90 and 100). Four replacements were done between dietary soybean meal protein and fish meal protein (30% : 60%; $0% : 50%; 50% : 40% and 60% : 30%) as fish meal: soybean meal, respectively, from the percentage of protein in each diet in a 4 X 4 factorial manner. Improvement of tilapia body weight gain, specific growth rate and feed conversion ratio were achieved when dietary P/E increased, while, decreased dietary P/E ratio reduced feed consumption and increased condition factor. The results for the above parameters of tilapia perfor‌mance increased significantly (Pc<0.05) with increasing fish meal protein on the expenses of soybean meal protein in all experimental diets, and highest values were obtained for fish fed diets containing 60:30 fish meal protein : soybean protein.