Background: Nitric oxide (NO) is synthesized from L-arginine by a family of enzymes known as nitric oxide synthases. Low concentrations of NO is essential in biology and physiology of spermatozoa, but high amounts of NO is toxic and has negative effects on sperm functions. Moreover, sperm membrane contains high concentrations of polyunsaturated fatty acids that are highly susceptible to oxidative damage that interferes with fertilization ability. Therefore, we investigated the correlation between levels of sperm malondialdehyde (MDA) and NO with sperm motility in male smokers. Methods: Semen samples were collected from normozoospermic smoker (n=64) and nonsmoker (n=83) men. The content of sperm lipid peroxidation was determined by measuring malondialdehyde (MDA). The sperm NO were also measured using Griess reagent. Data was analyzed by SPSS, (version 15.0), using independent t-test and Pearson analysis. Results: The mean MDA and NO concentrations in the sperm of normozoospermic male smokers were significantly higher than the control group or normozoospermic nonsmokers, (p