Description: The experiment was conducted on 48 Baladi ewes divided into four groups of 12 ewes each. Group 1 was kept as a control and was fed the basal diet consisting of roughage and concentrate mixture. Group 2 (ZnO 50 ppm) was fed the basal diet supplemented with 50 ppm zinc oxide. Group 3 (ZnO 100 ppm) and group 4 (ZnO 150 ppm) received the same basal diet supplemented with 100 and 150 ppm zinc oxide, respectively. Fertility traits of ewes and weight of lambs were recorded. Laparoscopic examination was carried out 3 weeks after the beginning of the experiment. Ovarian follicles were counted and classified according to their diameter into small (<2 mm), medium (2Ц4 mm) and large follicles (>4 mm). The numbers of corpora lutea on both ovaries as well as the ovulation rates were recorded. Data indicated that the supplementation of different levels of inorganic zinc oxide significantly increased the incidence of oestrus, pregnancy, lambing rates and resulted in shorter onset of oestrus as compared to the control group. A similar trend was observed in the mean body weight and daily gain of lambs born to supplemented ewes. A significantly (p<0.05) higher population of large follicles (2.5+-0.5 and 3.0+-0.6 follicles) were found in ewes supplemented with 100 and 150 ppm ZnO than in control and 50 ppm ZnO groups (1.0+-0.2 and 1.0+-0.3 follicles, respectively). The ovulation rate was significantly (p<0.05) higher in ewes supplemented with 150 and 100 ppm ZnO than those in 50 ppm ZnO and controls. In conclusion, the supplementation of 100 to150 ppm zinc oxide to the basal diet of Baladi ewes significantly improved the reproductive performance by decreasing the numbers of days to oestrus, increasing the incidence of oestrus, pregnancy, lambing rates and enhancing the body weight gain of their lambs. The number of large follicles and ovulation rates were also increased