Cigarette smoking is considered a social proplem as it constitutes a major health hazard to smokers. Smoking causes affection of the respiratiory system in the form of continuous cough and expectoration and chronic bronchitis. Cytogenetic abnormalities in the form of chromosomal breaks and sister chromatid exchanges are increased in smokers. Cotinine and 1-hydroxypyrene levels are much higher in smokers compared to nonsmokers. These increased levels of 1-hydroxypyrene in smokers indicate high risk of cancer susceptibility among them.