In this study, the effects of 17-ß-estradiol hormone on the zootechnic performances and sex ratio of Mozambique Tilapia (Oreochromis mossambicus. Peters, 1852) fry were investigated in order to initially produce functional phenotypical females and then super males. To this end, different E2 concentrations (50, 100, 150 and 200 ppm) were tested over a period of 45 days in a closed recirculating system. The evaluations showed that the female ratio was significantly (p value= 0.04 and α=0.05) higher in all treatment groups ranging from 61.90% to 86.36% compared to the control group. Growth was significantly higher (F value=22.78 and p value=0.00) in the control group compared to the treatment ones.