This clinical study investigated the possible associations of male sex hormone with the extensiveness of coronary artery lesions, coronary heart disease risk factors and ejection fraction of the heart. Ninety six Caucasian male subjects were recruited, 76 with positive and 20 with negative coronary angiograms. Early morning, prior to haemodynamic examination all of them had determined levels of total testosterone, free testosterone, free androgen index (FAI), sex hormone-binding globulin (SHBG), oestradiol, luteinizing hormone, follicle-stimulating hormone, plasma lipids, fibrinogen and glucose. The ejection fraction and the extensiveness of coronary lesions of each subject was assessed on the basis of x-ray examination results using Quantitative Coronary Angiography (QCA) and Left Ventricular Analysis (LVA) packages on the TCS Acquisition workstation, Medcon. Men with proven coronary heart disease had significantly lower levels of total testosterone (11.9 vs 21.2 nmol/l), free testosterone (45.53 vs 86.10 pmol/l), free androgen index (36.7 vs 47.3 IU) and oestradiol (109.4 vs 146.4 pmol/l). The level of testosterone was negatively associated with the DUKE Index. The most essential negative correlation was observed between SHBG and atherogenic lipid profile (low high-density lipoprotein, high triglycerides). Ejection fraction was substantially lower in patients (51.85 vs 61.30) (without prior myocardial infarction) with low levels of free-testosterone (23.85 vs. 86.10 pmol/l) and FAI (28.4 vs 47.3 IU). A negative correlation was observed between total testosterone, free testosterone, FAI and blood pressure, especially with diastolic pressure. Men with proven coronary atherosclerosis had lower levels of endogenous androgens than the healthy controls. For the first time in clinical settings it has been demonstrated that low levels of free-testosterone was characteristic for patients with low ejection fraction. Numerous hypothesies for this action can be proposed but all require a proper evaluation process. The main determinant of atherogenic plasma lipid was low levels of SHBG suggesting its main role in developing atheroscerotic lesions.