Purpose The aim of this study was to investigate the connection between erectile dysfunction (ED) and cardiovascular diseases and to test a novel visual-scale questionnaire (VEF) we propose for the assessment of erectile function. Subjects and methods Erectile function was assessed in 170 male cardiovascular patients under the age of 70 by the use of several selfadministered questionnaires: the International Index of Erectile Function-5 (IIEF-5); the Massachusetts Male Aging Study questionnaires (MMAS Sexual Activity Questionnaire and MMAS Single Question), and finally, VEF. Results Patients' mean age was 55.65 ± 9.97 y. The most common indications for hospitalization were coronary artery disease (CAD) (n = 82, 48%), and decompensated chronic heart failure (n = 30, 18%). The prevalence of ED as determined by IIEF-5 was 58% (n = 99). Patients with ED were on average 5.7 years older (P = 0.0001), had a higher frequency of diabetes (by 19%, P < 0.01), and a somewhat higher level of uric acid (by 72 μmol/l, P < 0.01). Results of the VEF correlated significantly with those of other questionnaires. Three different machine learning algorithms demonstrated a greater accuracy of VEF than IIEF-5 and MMAS Sexual Activity Questionnaire in predicting ED severity. Conclusion ED is highly prevalent among cardiovascular patients. The Visual Scale Erectile Function questionnaire (VEF) is a simple and valid tool, suitable for quick screening of this condition.