Objective — to study how patients with cardiovascular diseases (CVD) understand the most commonly used medical terms. Material and methods. The investigation enrolled 70 patients (mean age 60±11.5 years) admitted to hospital. All the patients suffered from coronary heart disease (CHD) and/or hypertension. Among those analyzed there were 39 men (mean age 60.8±12.8 years) and 31 women (mean age 59.2±9.8 years). All the patients had higher or secondary education. The patients were proposed to describe their understanding of 16 medical terms, which was rated using a 5-score system. Results. Most patients do not understand the meaning of the medical terms (scores of 1 or 2) or they understand the term descriptively (a score of 3). The patients do not understand the terms hypercholesterolemia (75.7%), cholesterol (67.1%); angina pectoris (58.6%), CHD (55.7%), atherosclerosis (54.3%), and risk factors (52.8%). The patients of both sexes understand the terms hypertension and diet aright, if incompletely or completely, in accordance with their official definition. The men have a more complete and right idea of the term cardiac rehabilitation and the women have that of the term tachycardia. Conclusion. A considerable number of patients with CHD and/or hypertension are unaware or misunderstand the meaning of the main cardiology terms that are used by physicians when talking with their patients and that are full in popular-science information. One of the ways to solve this problem is to actively involve patients with CVD in educational schools within rehabilitation and prevention programs.