The aim of this study was to evaluate the prevalence and incidence of venous diseases and the role of concomitant/risk factors for varicose veins (VV) or chronic venous insufficiency (CVI). The study was based in San Valentino in Central Italy and was a real whole-population study. The study included 30,000 subjects in eight villages/towns evaluated with clinical assessment and duplex scanning. The global prevalence of VV was 7%; for CVI, the prevalence was 0.86% with 0.48% of ulcers. Incidence (new cases per year) was 0.22% for VV and 0.18% for CVI; 34% of patients with venous disease had never been seen or evaluated. The distribution of VV and CVI in comparison with duplex-detected incompetence (DI) indicates that 12% of subjects had only VV (no DI), 2% had DI but no VV, 7.5% had DI associated with VV, 2% apparent CVI without DI, 3% DI only (without CVI), and 1.6% both CVI and DI. VV associated with DI are rapidly progressive and CVI associated with DI often progresses to ulceration (22% in 6 years). VV without significant DI (3%) and venous dilatation without DI tend to remain at the same stage without progression for a lengthy time. New cases per year appear to have a greater increase in the working population (particularly CVI) possibly as a consequence of trauma during the working period. In older age (>80 years), the incidence of CVI tends to decrease. Ulcers increase in number with age. Only 22% of ulcers can be defined as venous (due to venous hypertension, increased ambulatory venous pressure, shorter refilling time, obstruction and DI). Medical advice for VV or CVI is requested in 164 subjects of 1,000 in the population. In 39 of 1,000, there is a problem but no medical advice is requested and in only 61 of 1,000, the venous problem is real. In VV in 78% of limbs, there is only reflux, in 8% only obstruction, and in 14% both. In CVI, 58% of limbs have reflux, 23% obstruction, and 19% both. In conclusion, VV and CVI are more common with increasing age. The increase with age is linear. There was no important difference between males and females. These results are the basis for future real, whole population studies to evaluate VV and CVI.