This study was intended to reveal the usefulness of Zinc in endangered trout Salmo coruhensis and rainbow trout Oncorhynchus mykiss sperm. Spermatozoa were activated in sperm motility-activation solutions (NaCl, 0.3%; NaHCO 3 , 1%) containing the Zinc [Control (0), 0.5, 1, 2, 3, 4 and 5 mM]. The percentage and duration of motility, fertility and hatching rate were determined in sperm samples. Our results indicated that the percentage and duration of motility, fertility and hatching rate increased when activation solution containing NaHCO 3 was supplemented with 1 mM Zinc in rainbow trout (O. mykiss). On the contrary, motility rate in endangered trout (S. coruhensis) was increased by Zinc compared to control group. The percentage and duration of motility, fertility and hatching rate were affected by increasing concentrations of Zinc in endangered trout (S. coruhensis) and rainbow trout (O. mykiss) (p<0.05). In conclusion, sperm quality was affected by quantitative changes different concentrations of Zinc and the best results were obtained from a concentration of 1 mM for rainbow trout.