BACKGROUND Pneumonia is one of the most common infectious causes of death in children around the world, accounting for 14% of all deaths of children under five years of age. The study aimed to find out the prevalence of pneumonia among children admitted to the Department of Medicine of a tertiary care hospital. METHODS A descriptive cross-sectional study was conducted in the Department of Medicine of paediatrics tertiary care centre from 1 July 2021 to 30 June 2022 among children aged 2-59 months. Ethical approval was obtained from the Institutional Review Committee (Reference number: 94). Convenience sampling method was used. Data were collected from hospital records during the study period. Point estimate and 95% Confidence Interval were calculated. RESULTS Among 385 children, pneumonia was seen in 76 (19.74%) (15.76-23.72, 95% Confidence Interval) children. A total of 30 (39.47%) patients were in the age group of 2-11 months, 52 (68.42%) were males, 38 (50%) required O2 supplementation, 26 (34.21%) required transfer to the Intensive Care Unit, and 53 (69.74%) patients stayed for <7 days in the hospital. CONCLUSIONS The prevalence of pneumonia in children admitted to the Department of Medicine was found to be higher than similar studies conducted in similar settings, with higher prevalence in young infants and the male sex than other age groups and genders, respectively.