RELEVANCE In current clinical practice, there is a need for research to find new diagnostic tests for the purpose of determining the patients with the highest risk of death from pneumonia. Surfactant proteins SP-A and SP-D play a key role in the pathogenesis of the response to microbial invasion of lung tissue, which participate in a cascade of reactions of both innate and adaptive immunity, and therefore proteins SP-A and SP-D may be considered as markers of the severity of community-acquired pneumonia (CAP). AIM OF STUDY To evaluate the associations of surfactant proteins SP-A and SP-D in blood plasma with the severity of CAP. MATERIAL AND METHODS The study included 247 patients admitted to the therapeutic department. The group of patients with CAP (n=188) was divided into groups of severe (n=103) and non-severe (n=85) pneumonia. The comparison group (n=59) consisted of patients without acute and chronic diseases of the bronchi and lungs. The mean age (years, Me, 25th; 75th percentile) of patients was 55 (47; 68), 55 (47; 70), and 61 (37; 63) years, respectively. All patients underwent clinical, functional, diagnostic and laboratory studies (including determination of the content of SP-A and SP-D proteins by enzyme immunoassay). RESULTS In the group of patients with severe pneumonia unlike mild pneumonia, and group of comparison higher levels of proteins SP-A and SP-D were observed. Correlation analysis described below revealed statistically significant connection: protein SP-D — direct relation with leukocyte levels (r=0.320, p