OBJECTIVE: We evaluated the 5-year incidence of diabetes in an adult population from Greece. RESEARCH DESIGN AND METHODS: 3042 individuals (>18 years), free of cardiovascular disease, participated in the baseline examination (during 2001-2002). Of this sample, 1012 men and 1035 women were found alive at the time of follow-up, while 32 (2.1%) men and 22 (1.4%) women died during this period. The rest were lost to follow-up. Incidence of type 2 diabetes mellitus was evaluated in 1806 participants who did not have diabetes at baseline. RESULTS: The age-adjusted 5-year incidence of diabetes was 5.5% (men, 5.8%; women, 5.2%). A linear trend was observed between diabetes incidence and age (5.6% increases in incidence per 1-year difference in age, p<0.001). Multiple logistic regression analysis revealed that age (OR per 1 yr=1.04, 95% CI 1.02-1.06), waist (OR per 1 cm=1.02, 95% CI 1.01-1.003), physical activity (OR=0.62, 95% CI 0.35-1.02) and family history of diabetes (OR=2.65, 95% CI 1.58-4.53), as well as fasting glucose levels (OR per 1 mg/dl=1.05, 95% CI 1.03-1.07), were the most significant baseline predictors for diabetes, after adjusting for various potential confounders. Additionally, presence of metabolic syndrome at baseline evaluation 2.95-fold the risk of diabetes (95% CI 1.89-4.61), and showed better classification ability than the model that contained the components of the syndrome (ie, correct classification rate: 94.5% vs. 92.3%). CONCLUSION: Our findings show that a 5.5% incidence rate of diabetes within a 5-year period, which suggests that the prevalence of this disorder in Greece is rising. Aging, heredity, and metabolic syndrome were the most significant determinants of diabetes.