Aim:Smoking poses a serious threat to public health. The aim of this study was to investigate the relationship between smoking and DNA damage in lymphocytes. A potential genotoxic effect of cigarette smoking was analyzed with the nine comet assay parameters including comet length (CL), comet intensity (CI), head length (HL), head intensity (HI), tail length (TL), tail intensity (TI), DNA tail (DNAt), tail moment (TM) and olive tail moment (OTM). For the first time in this study, smokers were grouped as female and male, and nine comet parameters were used.Material and Method: 120 volunteers (60 non-smokers, 60 smokers) were monitored in the way of DNA damage in blood lymphocytes. The levels of DNA damage was measured by BAB Bs Comet Assay system.Results: Highly significant associations were found between the non-smoker and smoker groups for CI, TL and OTM comet parameters (p<0.01). Smoker female group had higher CL, CI, HL, HI, TL, TI (p<0.01) and TM (p<0.05) with regard to DNA damages than the non-smoker female group. In contrast, only DNAt, and OTM comet parameters were statistically significantdifferences between the smoker male and non-smoker male groups (p<0.05). When the smoking index (SI) of all the blood samples from females were compared based on all studied comet parameters, statistically significant association was found except for TM. On the other hand, the blood samples taken from males were statistically significant in terms of CL, HL, HI, TI and OTM parameters (p<0.05). Conclusion:Consequently, it can be said that, smoking cause DNA damages and females are more sensitive to the effect of the smoking than males.