BACKGROUND According to the world Health organization, approximately one third of the world` population older than 15 years are smokers. Evidences indicate that both in men and in women, cigarette smoking affects reproductive health more than the consumption of caffeine or alcohol in comparable doses. The mechanisms according to which tobacco affects spermatozoa are poorly understood. Some of the studies focused on the relation between cigarette smoking and the principal semen analysis, variable such as concentration, Morphology and Motility. In this study, we compared the sperm parameters between smokers and non-smokers. METHODS This case control study was done on men from infertile couples who were referred to Yazd research and clinical center for infertility but the cause of infertility was not the male factor. The semen analysis was compared between the smokers and non-smokers. RESULTS 151 infertile men were enrolled in the present study. 98 non-smokers and 53 smokers the mean age of patients was not significantly different between groups. There were no significant differences among groups according to sperm concentration (P-Value 0.108), Morphology (P-Value 0.138) and Motility (P-Value 0.082). Also there were no significant relationship between sperm parameters and the amount of cigarettes people had used (based on Pack/year scale). CONCLUSIONS Semen parameters (Morphology, Motility and concentration) were lower in smokers but there were no significant differences between groups.