The goal of this investigations was to analyze the sexuality of cardiological patients which do or do not have diabetes on top of their primary disease (heart infarction, coronary artery and/or valvulae operation) with respect to their functional status. The correlation between their perception of their disease and their sexuality, has been investigated by means of our Questionnaire on sexuality. The physical status of patients, important for conducting daily activities as well as for their sexual activitiy, has been investigated using the following tests: ergometry test, spirometry, Borg scale after conducting aerobic training, physical exercise and bicycle-ergometry, both at the beginning and at the end of cardiological rehabilitation. We investigated 60 patients aged 40 to 75 years. The independent variables were: age, sex, height, body mass, professional status, and education level. The dependent variables consisted of results of ergometry testing, spirometry, Borg scale and Questionnaire on Sexuality. The results were analyzed using Statistica (Version 13.5.0.17, 1984-2018 TIBCO Software Inc.) and Microsoft Excel 2010, as well as descriptive statistics (arithmetic means, standard deviations and percentages). Our results have confirmed the majority of our hypotheses – that diabetes decreases sexuality in cardiological patients, and that the sexuality of cardiological patients is not decreased after the rehabilitation leading to better physical condition. However, due to the too small number of female patients involved in this study, we could not test the hypothesis that the sexuality is more decreased in men than in women.