In this study, it is aimed to test the possible effects of smoking on enzymes and chromosomes of volunteers. The chromosomes from human periferal lymphocytes of smoking and non-smoking volunteers were obtained, caryotype analysis were carried out by G-banding and chromosome aberration were examined by CA technique through spontaneous and positive mutagene induction for all donors. Again for all donors, the chromosomes were labeled with some centromere probes for clinical purposes through application of FISH technique. Additionally, GST enzyme activities were determined on the all blood samples. As a result of obtained data, parameters which tested on smokers and non-smokers were evaluated comparatively. It is revealed that, GST enzyme activities were increased due to smoking, but it is not pose any harm in chromosomes.