Introduction. Community-acquired pneumonia is a leading cause of morbidity and mortality worldwide, and is strongly influenced by comorbid conditions. Obesity is associated with higher mortality rate directly proportional to higher body mass index. Obesity is also associated with an increased risk of acquiring infections such as community-acquired pneumonia. Aim of the study. To evaluate the obesity influence on clinical manifestations in patients with severe community-acquired pneumonia. Materials and methods. The retrospective case-control study was based on case histories analysis of patients hospitalized with severe community-acquired pneumonia in the Department of Internal Medicine, Sfânta Treime Municipal Hospital between years 2018 and 2019. The study were included 82 patients aged between 34 and 83 years, divided in two groups: group 1 (41 patients with obesity) and group 2 (41 normal weight patients). Results. Inavasive ventilation was necessary in 34% (28/82 patients), 16 patients with obesity and 12 normal weight patients (19% vs 15%) (p>0.05). The mean duration of inavasive ventilation was 5.7±2.5 days in obese vs 5.5±3.7 days in normal weight patients. Among 82 patients, the main duration of hospitalization was 14.5±5.2 days. The obese patients lengths of hospital stay was 15±3.2 days vs 13±2.4 days in normal weight patients (p<0.05). Duration of antibacterial therapy was 19.3±7.3 days in obese and 18.2±5.8 days in normal weight patients (p<0.05). The group of obese patients consisted of obesity class 1- 24.4% (10/41 patients), class 2 - 26.8% (11/41 patients) and class 3 - 48.7% (20/41 patients). The presence of complications in obese was reported in all the cases, of them - 100% of acute respiratory failure, 14.6% of ARDS, 39% of pleural effusion, 22% of cardiogenic pulmonary edema, 7% of sepsis and 12% of multiple organ dysfunction syndrome. Conclusions. The study revealed that obesity was positively associated with a longer hospitalization stay and longer duration of antibacterial therapy. No association was found between obesity and more frequent need for mechanical ventilation. The most severe complications were registered in patients with class 3 obesity.