Quality of life refers to the well-being of individuals or populations, encompassing both positive and negative aspects of their lives at a given moment. Over the past two decades, interest in studying quality of life has significantly increased, partly due to the World Health Organization's (WHO) revised definition of health, which now includes not only the absence of disease but also overall physical, mental, and social well-being. Additionally, there is a growing need to assess the effectiveness, safety, and cost-effectiveness of new therapies, taking into account the patient's subjective sense of health. The aim of this study is to determine how the component of physical health and self-assessment affect the quality of life of patients with various chronic diseases. The study examined the relationship between self-assessment of quality of life and health, differences in mobility, and satisfaction with performing daily activities among patients with cardiovascular and rheumatic diseases. The study involved 391 participants with chronic diseases, and participation was anonymous and voluntary. Data were collected using the validated WHOQOL-BREF questionnaire from the World Health Organization, which assesses four domains of quality of life through 26 questions. Statistical analysis was conducted using Statistica 14.0.0.15 (TIBCO Software Inc.). Variables from the questionnaire were expressed on an interval scale, while sociodemographic data were on a nominal scale. Hypotheses were tested using the Kolmogorov-Smirnov test, followed by parametric and non-parametric Mann-Whitney U tests, with a significance level of p<0.05. : The results indicated a significant correlation between self-assessment of quality of life and health among participants with cardiovascular and rheumatic diseases. No statistically significant differences were found in mobility or in performing daily activities between the groups. Measuring quality of life related to physical health is important for shaping health policy. Self-assessment of quality of life enhances treatment outcomes, optimizes costs, and provides crucial information for the development of health services.