The objective of the present study was to determine the dietary iron requirement for the Nile tilapia, Oreochromis niloticus fmgerlings in intensive fish culture system. O. niloticus fmgerlings (25.36±0.11g) were stocked in fiberglass tanks (lm3) under water running system at a density of 40 fish/m3 with a feeding level of 3% of body weight. Six purified diets containing different iron levels (0, 200, 400, 800, 1200 &1600 mg Fe/ Kg) in a form of ferrous sulphate were tested on the Nile tilapia for 8 weeks. Results revealed that FBW and SGR were the highest (P<0,05) in the fish group fed on the diet supplemented with 1200mg Fe /Kg and the lowest were recorded in fish fed on the iron free diet. Each of K and FI were insignificantly affected by dietary iron levels. The lowest value of FCR was recorded for fish fed on 1200mg Fe/ Kg diet. The results of the present study revealed that, the group offish fed 1200-mg Fe /Kg diet had significantly(P<0.05) the highest value of average daily gain in weight PPV and ER. Red blood cell count, haemoglobin and haematocrit values were increased with increasing the level of iron and significantly affected by dietary iron levels. The highest value of MCH was recorded for fish fed 1200 mg Fe /Kg diet. The lowest values of RBCs, Hb, ,Hcts MCVr MCH and MCHC were recorded for fish fed on iron free diet. TotaL plasma proteins and plasma glucose values were not significantly affected by increasing dietary iron level, while plasma cholesterol increased significantly by increasing the level of iron in the diet. The results of the present study suggest that iron supplemented to the diet up to a level of 1200mg Fe/ Kg diet from ferrous sulphate improves the growth performance and haematological parameters of O. niloticus fingerlings.