The ability to perform basic activities of daily living (ADL) and instrumental ADL (IADL) is an essential indicator of the level of functional capacity in old age. The purpose of this paper was to evaluate reliability and validity of the self - reporting method in detecting functional difficulties among elderly persons with cardiovascular diseases. The Groningen Activity Restriction Scale was used to assess the limitations in functional capacity. The sample consisted of patients over the age of 65 with hypertensive disease, angina pectoris, ischaemic heart disease, degenerative valvular disorders, peripheral arterial disease, cardiac arrhythmias, cardiomyopathy and heart failure. The Cronbach’s alpha internal consistency coefficient was calculated for the total result. Differences in outcome with respect to age, educational level, marital status, and medical diagnoses of participants were compared by means of a t-test or one-way ANOVA. In the group of ADL, participants reported difficulties in climbing stairs (M=2.14, SD=1.07) and caring for feet and toenails (M=2.17, SD=1.27), while in the group of IADL, difficulties were present in performing heavier household chores (M=2.51, SD=1.31) as well as ironing and washing clothes (M=2.20, SD=1.29). Calculation of the Cronbach’s alpha coefficient points to a high degree of internal consistency for this scale on a chosen sample (α=0.95). The use of a validated self-reporting tool may be a valuable and reliable way for assessing the functional capacity of elderly persons with chronic diseases. The findings of this study indicate the possibility of using this method for prognostic purposes in patients with cardiovascular diseases. Introduction of instrumental support measures in a timely manner has a crucial role in delaying the progression of functional dependence.