Diabetes, a comprehensive genetic disease, is principally due to the deregulation of glucose levels in the blood. In addition to contemporary epidemiological studies, systematic substantiation suggests that long-term diabetes leads to cancers due to a variety of reasons. In this study, blood samples were collected with informed consent from confirmed type I diabetic (T1DM, n=25) and type II Diabetic patients (T2DM, n=25) with equal numbers of controls. Further depending on the lifestyle habits they were subdivided into smokers/non-smokers and alcoholics/non-alcoholics. Chromosomal assays were performed for these cases and it was found that there was a significant increase in chromosomal aberration frequency in diabetic patient groups who are exposed to smoking and alcohol than that of normal diabetic groups (T1DM and T2DM). On the other hand, patient groups who were non-smoking and non-alcoholics also showed higher chromosomal aberrations when compared to that of controls. While the mechanisms for these increased chromosomal aberrations in diabetic groups are not clear, they may be due to increased oxidative stress leading to oxidative damage and resulting in genomic instability, which in turn may contribute to an increased risk for cancer.