The risk of coronary heart disease (CHD) was studied in 4405 Finnish middle-aged working men in different occupations according to their sense of coherence (SOC). The study design was prospective and the follow-up time was eight years. Clinical findings such as total cholesterol, systolic blood pressure and body-mass index showed differences when comparing blue and white collar workers. Lifestyle factors such as smoking also differed, but leisure time physical activity depended on SOC. In the white collar work environment the low SOC tertile had a high CHD incidence of 20.1 per 1000 person-years; the incidences in the medium and high SOC tertiles were 10.9 and 12.3, respectively. A similar effect was not observed in the blue collar work environment. There, contrary to theoretical expectations, the low SOC tertile had the lowest incidence of CHD. The difference in the CHD incidence pattern depended on the blue and white collar dichotomy and not on the branch (state agencies vs. industry). The SOC had a salutogenic effect among white collar workers, but failed to have any consequent effect on the health of blue collar workers. Further study is needed to look at the psychosocial factors among blue collar workers.