The aim of the paper was to detect the factors leading to the death of patients classified as mild on the CURB-65 scale. We performed a retrospective analysis of 1412 case histories of hospitalized community-acquired pneumonia patients in all hospitals in the Tomsk Region in 2017. All patients were categorized into different groups based on lethality and CURB-65 score. We analyzed age, gender, and laboratory indicators. Significant indicators of an adverse outcome were identified. It is necessary to modify the scale and take into account a larger number of indicators.