Abstract Background The importance of health-relatedquality of life (HRQoL) and improving functional status in reducing risk factors of myocardial infarction (MI) has also been increasingly recognized. Purpose This study aimed to examine the level of quality of life (QoL) in patients after myocardial infarction (MI) in relation to the degree of functioning in chronic disease. Methods This was a cross-sectional, single-centre study. The study was conducted among 231 patients who were hospitalized for myocardial infarction (MI) after percutaneous coronary intervention (PCI). The WHO Quality of Life Questionnaire (WHOQOL BREF) andthe Chronic Disease Functioning Scale(FCIS) were used. Results The Spearman's correlation coefficient showed a statistically significant correlation (coefficient value 0.5 < |r/rho| ≤ 0.7) between general functioning in chronic disease and the average QoL (rho = 0.56;p < 0.001)and somatic QoL levels(rho = 0.52;p < 0.001), as well as a moderately strong positive correlation with the QoL level on the psychological domain (rho = 0.50;p < 0.001), social domain (rho = 0.48;p < 0.001) and environmental domain (rho = 0.43;p < 0.001). Conclusion Identifying the chronic disease functioning indicator in post-MI patients in relation to HRQoL allows for targeted counseling and secondary prevention of ischemic heart disease (IHD), which translates into a reduced risk of further cardiovascular events and related rehospitalization.