A cross-sectional study in a sample of 3,291 healthy workers was performed in May 1997 to assess the prevalence of obesity (BMI > or = 30 kg/m2) in a working population, and to compare prescription of antihypertensive drugs in obese and non obese subjects. Obesity was found in 7.4% (245) subjects and morbid obesity concerned 0.4% of the total sample (mean age 37.6 +/- 9.7 [SD] years, 52.4% of males). Risk of obesity was significantly associated with age, male sex, professional classes (higher in blue collars workers, lower in senior executive), business travels, atypical schedules, professional and private difficulties. Albeit the prevalence of drug users (49.7%) was similar whatever the BMI, obese subjects used a higher number of drugs than non obese (2.0 +/- 1.2 versus 1.6 +/- 0.9, p < 0.001). Risk of consumption of cardiovascular drugs was higher in obese than in non obese subjects (OR 2.9, 95% CI [2.2-4.1]). After adjustment on confounding factors, obesity increased specific drug use such as angiotensin converting enzyme inhibitors (OR 3.3, 95% CI [1.7-6.4]), beta-blocking agents (OR 2.83, 95% CI [1.01-8.01]), calcium channel blockers (OR 2.44, 95% CI [1.06-5.63]) or diuretics only in women (OR 5.7, 95% CI [2.1-16.3]). Prescribed antihypertensive drugs were different in obese (beta-blockers = angiotensin converting enzyme inhibitors > diuretics > calcium channels blockers) and non obese (angiotensin converting enzyme inhibitors > calcium channel blockers > diuretics > beta-blockers) subjects.