A steady increase in the prevalence of overweight (OW) is causing concern since this is an important risk factor for many diseases, including cardiovascular diseases (CVD) that have remained the main cause of death worldwide for many years. Objective — to investigate the impact of OW and obesity on overall and cardiovascular mortality risks. Material and methods. A 27-year cohort prospective follow-up study was conducted in an unorganized Tomsk population (n=1546) aged 20—59 years. At the first stage, the prevalence of OW and obesity was studied. A body mass index of ≥25 kg/m2 was considered OW and that of ≥30 kg/m2 was obesity. During a repeated study, overall and cardiovascular mortality rates were analyzed and the prognostic value of OW and obesity for assessing the risk of death was investigated. Results. OW persons were found to have a higher risk for overall (the relative risk (RR) was 1.25 in the general population and 2.42 in women) and cardiovascular (RR=1.8 in the general population; RR=4.8 in the women) mortality. The obese people had also a higher risk for overall (RR=1.46 in the general population; RR=2.18 in the women) and cardiovascular (RR=2.03 in the general population; RR=2.92 and 1.97 in the women and men, respectively) mortality. There was a direct correlation between the mean body mass index and mortality rates from CVD and all causes in both gender groups. The mortality risk was shown to be also higher in the young persons; and OW and obesity were of worse prognostic value in the women than those in the men. Conclusion. The 27-year prospective cohort study has shown the considerable impact of OW and obesity on overall and cardiovascular mortality risks in women, as well as the contribution of obesity to CVD mortality rates in men, which should be taken into account when planning therapeutic and preventive measures.