The present study was aimed to investigate the effects of organic and inorganic zinc supplements on histomorphometric features of the lambs’ testis using stereological methods. Twelve Sanjabi ram lambs weighting 20–25 kg at an average age of 3–3.5 months were divided into three groups. The first group received basal diet while the diets of the second and third groups were supplemented with 40 mg/kg DM zinc methionine and zinc sulphate, respectively, for 70 days. The data revealed that body weight gain was significantly (P≤0.05) lower in inorganic zinc group compared to the control and organic zinc groups. Significant increase (P≤0.05) in the testis weight, testis volume, tubule vo¬lume, tubule length, tubule diameter and increased number of Leydig cells were observed in organic zinc supplemented lambs compared to both the control and inorganic zinc groups. Both organic and inorganic zinc groups exhibited significantly increased height of germinal epithelium compared to the control group, but there was no significant (P>0.05) difference between them. Interstitial tissue volu¬me did not show significant changes. It can be concluded that the organic form of dietary zinc (Zn methionine) showed a better response in improving testis structural parameters as compared to the inorganic form of Zn (zinc sulfate).