STUDY OBJECTIVE--The aim was to examine the relationship between level of education, lifestyle, and morbidity in two groups of male white collar workers, and to determine whether any differences found could be related to objective differences in working conditions. DESIGN--The study was a survey of a random sample of commercial travellers and a sample of men with sedentary occupations, representing two different groups of white collar workers. Survey interviews were conducted during the annual compulsory medical examination. Subjects were classified into three levels of education and differences according to level of education were studied in relation to 40 frequent health problems, lifestyle variables, body mass index, height, and working conditions. SUBJECTS--There were 1364 men in the commercial traveller group, mean age 39.5 years, and 525 men in the sedentary group, mean age 36.2 years. There were 22 exclusions because of unclassifiable levels of education and four refused to be interviewed. SETTING--The study took place in 11 towns in France. MAIN RESULTS--When age was taken into account there were only minor differences in the prevalence of health disorders. Lifestyle variables and height were clearly related to the level of education. Observed differences could not be explained by constraints or declared difficulties in working conditions. CONCLUSIONS--Differences in health practices related to level of education are observed even in groups that are relatively homogeneous socially. Lifestyle may be important as an intermediate determinant of health disorders among less educated people.