Smoking is one of the most important risk factors of atherosclerosis and ischaemic heart disease. Endothelial dysfunction is a pathological result of smoking. The aim of the study was to examine the influence of cigarette smoking on biochemical parameters of endothelial function in persons with angiographically confirmed coronary arteries atherosclerosis. The study group included 117 men: 55 patients (mean age 58.8 +/- 10.4) with ischaemic heart disease and 62 healthy subjects (mean age 47.1 +/- 9.3) of control group. In all patients blood lipid concentrations, biochemical parameters of endothelial function (nitric oxide, endothelin-1, sICAM, selectin-E), and inflammation parameters (interleukin-1 beta, interleukin-6) were measured. In a group of smoking patients both: with atherosclerosis and in control subjects nitric oxide (NO) concentrations in serum were decreased in comparison to nonsmokers. In patients with diagnosed coronary arteries atherosclerosis interleukin-6 and sICAM concentrations were increased in comparison to non-smokers. It is concluded that cigarette smoking activates or maintains inflammatory reaction in vessels with atherosclerotic changes.