Background: Cytokines may play a role in the pathogenesis of atherosclerosis and coronary artery disease (CAD). Methods: We examined serum concentrations of selected pro- (TNFalpha, IL-2) and anti-inflammatory (IL-10) cytokines, and soluble forms of TNF receptors (sTNFR 1 and sTNFR 2) by ELISA in 45 patients with stable exertional angina (group 1), 32 patients with unstable angina (group 2), and 20 healthy subjects (group C). Results: Serum concentrations of both TNFalpha (group 1, 18.3; group 2, 17.2 pg/ml; P<0.001) and IL-10 (group 1, 46.1; group 2, 41.5 pg/ml; P<0.05) were significantly higher in patients with CAD than in group C (8.3 and 14.3 pg/ml, respectively). sTNFR 1 serum level was higher in group 1 (1399.6; P<0.05) than in healthy volunteers (1093.9 pg/ml). In turn, the serum level of IL-2 was significantly higher in unstable patients than it was in groups 1 and C (89.4, 59.8 and 52.8 pg/ml, respectively). In group 1, both TNFalpha and IL-2 correlated with serum lipids. Conclusions: Patients with CAD, irrespective of the form of the disease, have higher serum levels of pro- and anti-inflammatory cytokines than control subjects. Increased concentrations of IL-2 in unstable angina may suggest additional immunologic activation. The pro-inflammatory cytokine levels seem to be related to lipid disturbances.