Introduction: Pneumonia is one of the most common causes of paediatric hospitalisations. Aim of the study: To analyse antibacterial treatment of pneumonia in children hospitalised in 2017 at the Department of Paediatrics, Paediatric Nephrology and Allergology of the Military Institute of Medicine in Warsaw. Material and methods: Medical documentation data of 360 children with clinical diagnosis of pneumonia was subjected to a retrospective analysis. Age, gender, antibiotics used before and during hospitalisation and time of treatment were considered. Results: Of all the children hospitalised at the Department (2,207), 360 pneumonias were reported (16.3% of all hospitalisations). The mean total time of antibiotic therapy was 10.76 ± 3.57 days. Out of 176 children (48.9% of all pneumonias) who reported to a general practitioner 91 (51.7%) received symptomatic treatment and 85 (48.3%) – antibiotic. On admission to hospital the type of antibiotic treatment was modified for 63/85 children (74.1%) and the form of antibiotic delivery was changed from oral to intravenous for 74/85 (87.1%). Antibacterial treatment in general practice was compliant with recommendations in 18/85 children (21.2%) and during hospitalisation – in 69/360 patients (19.2%). Conclusions: The most common infectious cause of paediatric hospitalisations was pneumonia. In general practice a significant problem is to diagnose community-acquired pneumonia with bacterial aetiology because of an uncharacteristic onset of symptoms. There is significant discrepancy between the everyday practice and recent guidelines on antibiotic use.