A prospective transversal study was undertaken by occupational health physicians on more than 4,000 individuals including almost 800 women working in the same company with the following aims: a) to compare the prevalence of a certain number of classically recognized cardiovascular risk factors in 2 types of populations, service versus manufacturing industries, in the Paris region; and b) to understand these populations better so as to develop educational and information campaigns specifically adapted to their needs. Several elements were recorded in a computer data bank during the physical examination: blood pressure, blood cholesterol, smoking history, blood triglycerides, blood sugar, the ratio of measured to theoretical weight and physical activity. For each of these parameters, a value above a determined threshold level was defined as a risk factor. For men working in service industries, the percentages of heavy smokers (24%), hypercholesterolemia (18%), and hyperglycemia (7%) were significantly higher than in the manufacturing sector (19.3, 15 and 2.4%, respectively). In manufacturing industries, the percentages of men with hypertension (15%), hypertriglyceridemia (10%), who were overweight (24%) or had a low high density lipoprotein level (10%) were significantly higher than in the service sector (3.1, 7.5, 20 or 8.2%, respectively). The percentage of women smoking more than 20 g of tobacco per day (25.5%) in the service sector was significantly higher than that in manufacturing industries (4.25%). In contrast, in the manufacturing sector, the percentages of hypertensive (6%) and obese (24%) women were significantly higher than those in the service industries (1.1 and 16%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)