Hyponatremia is the most common electrolyte imbalance seen in clinical practice and a common laboratory findings in children with community acquired pneumonia. This study aimed to find out relationship between clinical profile, severity and outcome of community acquired pneumonia with hyponatremia in children aged 2-60 months. This descriptive cross-sectional study was done in pediatrics department of Mymensingh Medical College Hospital, Bangladesh. Study period was 6 month from November 2016 to April 2017. Data were collected from 2 months to 60 months old children who fulfill the selection criteria. In this study sampling technique was purposive. Detailed history was taken, and meticulous examinations and relevant investigations were performed. 100 patients with community acquired pneumonia were enrolled, 34.0% patient had hyponatremia and 66.0% patients had no hyponatremia. Hyponatremia is more marked (45.5%) in severe pneumonia followed by moderate pneumonia (33.3%) and no hyponatremia found in mild pneumonia. Mean temperature, respiratory rate, heart rate, head nodding, nasal flaring, grunting, stridor, cyanosis, convulsion, feeding problem, Poor air entry were significantly higher in patient of pneumonia with hyponatremia when compared to patient of pneumonia without hyponatremia. Mean duration of symptoms and mean duration of hospital stay were also significantly higher in patient of pneumonia with hyponatremia. The mean serum sodium concentration was 132.18±1.51mmol/L in hyponatremic patients and 137.91±1.94mmol/L in normonatremic patients. Mean values of total leucocyte count, ESR, and C-reactive protein were significantly higher in patient of pneumonia with hyponatremia. Serum hemoglobin was significantly lower in hyponatremic patients than normonatremic patients. Maximum (55.9%) patients of community acquired pneumonia (CAP) with hyponatremia had patchy opacity, 26.5% had consolidation, 11.8% had interstitial opacity and 5.9% had pneumatocele. All the patients were treated with appropriate antibiotics and fluid and discharged after complete recovery without any complication. There was no death in the study population. From this study we can conclude that, hyponatremia is directly related with the severity of community acquired pneumonia (CAP). The intensity of clinical profile and investigation findings are also directly related with the severity of pneumonia.