Aim. To evaluate the impact of community-acquired pneumonia (CAP) on short-term and long-term prognosis in patients hospitalized with signs of chronic decompensated heart failure (CDHF). Subjects and methods. A total of 852 cases were admitted to therapy/cardiology hospital with signs of CDHF during a year. Results. Among the patients hospitalized with signs of CDHF, the prevalence of CAP was 16.5%. This indicator did not depend on the age of hospitalized patients. Among the multisystem disorders, hypertension, different forms of coronary heart disease, diabetes mellitus, and chronic obstructive pulmonary disease were more common in the patients with CAP. The presence of the latter in a patient with CDHF statistically significantly increased the length of hospital stay (13.1 versus 11.9 days; p = 0.009) and also the probability of rehospitalization during a year (odds ratio (OR) 1.9; p = 0.02). The presence of CAP in a patient with CDHF resulted in an increase in mortality rates (OR 13.5; p < 0.001); moreover, the highest risk of a fatal outcome was noted on day 1 of hospitalization (12.7%). During one-year follow-up, the risk of death in patients hospitalized with CDHF and concomitant pneumonia proved to be higher (OR 4.8; p < 0.001) than in those without pneumonia.