Cigarette smoking is a major public health problem that is associated with high morbidity and mortality. This study was designed to investigate the relationship between cigarette smoking and concentration of testosterone in the urine. Forty young men age between 23 to 31 years were used for this study. The subjects were divided into two groups of 20 controls (noncigarette smoker) and 20 experimental groups (cigarette smoker). 5ml of mid-stream urine was collected from each subject at 0700 hour and urine testosterone concentration was estimated using enzyme immunoassay method. The result showed that the urinary testosterone concentration of non-cigarette smokers was 4.35±0.52 ng/ml, while the concentration in cigarette smokers was 2.81±0.38 ng/ml with p<0.01. It is concluded that cigarette smoking reduced urinary testosterone concentration among cigarette smokers.