In modernized lifestyle smoking is one of the trendy, psychological, and socioeconomic scenarios of young adolescents mainly in the age of the reproductive stage. Based on a number of cigarettes smoked, age, and duration of the smoke, the study aims to search for the profound effects of smoking and its impact on semen parameters, sperm‐DNA integrity, and fragmentation of sperm DNA with cotinine and apoptotic caspase‐3 marker in the seminal plasma of fertile and infertile smokers. To determine oxidative damage by 8‐hydroxy deoxyguanosine (8‐OHdG) from isolated sperm DNA (steps: reactive oxygen species washing by nitro blue tetrazolium (NBT), sperm lysis, salt digestion, ethanol washing, and finally with high‐performance liquid chromatography analysis). Level of DNA fragmentation (percentage) in native and intact DNA, the activity of caspase‐3 in infertile smokers will be compared with the control group of nonsmokers. Also, the sperm viability was visualized by eosin‐nigrosin and aniline blue staining. Cotinine is one of the best markers of smoking. The cotinine level (2224.24 ± 1.19 *** ng/mL), when abundant it negative correlates with morphology and rapid motility in infertile smokers than nonsmokers. Gel preprogram measured the sperm integrity and was found to be less in smokers than nonsmokers. The spermatic oxidative marker 8‐OHdG was high and gave an R 2 value of 0.9104 with morphology and 0.9007 for rapid motility of infertile sperm, respectively. Infertile smoking subjects (<10 cigarettes/day) had significant changes increase in sperm fragmentation, caspase‐3, and cotinine while negative impact with motility, morphology, and pH of semen compared with fertile, infertile nonsmoking subjects. Cotinine, a biomarker of nicotine and also identified as a proximate metabolite in most of the tobacco exposure. Liver metabolized cotinine is reached blood‐testis barrier through the bloodstream and affects testicles. It may damage testicular tissues of Leydig cells and Sertoli cells in smokers and disrupt the testicular endocrine system and it leads to spermatogenic failure.