Recent findings suggest that inflammation and cytokines regulation may play a role in the pathogenesis of atherosclerosis and coronary heart disease. The aim of this study was to assess serum concentrations of selected pro- (TNF alpha) and antiinflammatory (IL-10) cytokines in patients with coronary heart disease. We studied 29 patients with coronary heart disease: 14 with stable angina (group I) and 15 with unstable angina (group II). The control group (group K) consisted of 10 healthy subjects. Patients with inflammatory diseases, previous myocardial infarction (last 6 months) and with ECG abnormalities, that would invalidate ST-segment analysis, were excluded from examined groups. We evaluated: clinical state of patients and results of some diagnostic examinations (lipids, ECG, echocardiography, coronary angiography, concomitant diseases). In each patients serum levels of TNF alpha and IL-10 were measured according to the special protocol by ELISA. The mean serum concentrations of TNF alpha and IL-10 were significantly higher in group I (respectively: 18.75 +/- 11.7 pg/ml, 89.0 +/- 114.9 pg/ml) and II (14.21 +/- 5.9 pg/ml, 49.38 +/- 72.9 pg/ml) in comparison to the healthy subjects (9.41 +/- 1.7 pg/ml, 9.69 +/- 4.5 pg/ml). We found positive correlations between mean TNF alpha and IL-10 concentrations in group II (48 hours after last symptom) and between mean TNF alpha concentration and LVM (left ventricular mass), LVMI (left ventricular mass index) in group I. The concentrations of TNF alpha and IL-10 did not correlate with other clinical parameters. The results of our study suggest that serum concentrations of pro- (TNF alpha) and antiinflammatory (IL-10) cytokines may be increased in patients with stable and unstable angina. These increased concentrations do not reflect the clinical state of patients.