The aim of the study was .to examine the relationships between concentrations of zinc in serum and seminal plasma and semen quality among infertile and fertile men. On the other hand, clarification of the possible impact of zinc in male reproductive system. 58 male (infertile group) parteners of couples who were undergoing investigations for infertility and 37 men(fertile group) whose wives were pregnant and have normal sex life. Seminal fluid and the reproductive hormones analysis were determined for both groups. Also , The subject's serum and seminal plasma concentration of zinc were determined by used colorimetric analysis. All the semen properties (count, motility, morphology) for the infertile men were lower than those for the fertile men. Except for serum testosterone hormone, all the other reproductive hormones (Luteinhing hormones LH. Follicle stimultating hormone FSH) for Infertile men did not differ from those for the fertile men. It was found that the means1 of seam and seminal plasma zinc concentrations were lower in the infertile men compared with those in the fertile men. An attempt to correlate serum zinc concentration with seminal plasma zinc concentration in both group failed as no correlation could be found. Also, no significant correlation was found between zinc concentrations in serum and seminal plasma with semen properties. On the basis of the finding of this study and those of other reports, zinc may contribute to fertility through its direct or indirect effect on spermatogenesis.