A study was conducted to evaluate the need for dietary mineral supplementation of Nile tilapia cultured under a supplementary feeding regime. Thirty sex-reversed all male Nile tilapia (23g ± 0.7) were stocked in 1 m 3 netcages suspended in an earthen pond fertilized weekly with urea and triple super phosphate at rates of 4 kg N and 1 kg P ha - 1 , respectively. The fish were fed experimental diets supplemented with a complete mineral premix (control) and with incomplete mineral premixes in which specific macro (Ca, P, Mg, Na, K) and micro-minerals (Fe, Zn, Mn, I) were omitted from the mineral premix. Among the minerals studied, the addition of phosphorus was found to significantly affect tilapia weight gain, feed conversion ratio, and protein efficiency ratio.