Several recent studies have indicated that shift work is associated with increased risk of coronary artery disease. In this cross-sectional study 361 shift workers were examined with respect to some major risk factors for coronary artery disease; 240 day workers constituted the reference group. A higher proportion of shift workers smoked (54 versus 39%). Shift workers also had significantly higher levels of serum triglycerides (1.61 versus 1.43 mmol/l). Body mass index and the blood pressure and total cholesterol levels did not differ between the groups. Multiple regression analyses demonstrated that shift work was significantly related to serum triglyceride levels also when age, smoking, body mass index, and other variables were controlled for. It was concluded that shift work is associated with several risk factors for coronary artery disease.