Background: community-acquired Pneumonia (CAP) is one of the frequent causes of hospital admission, whereas hyponatremia is a common electrolyte abnormality in hospitalized patients and associated with considerable morbidity and mortality. Aim of the study: purpose of this study was to evaluate serum levels of sodium in children with CAP. Patients and Methods: a total of 200 children included in the study were classified into two groups as follow: Group (I) Cases group: Included 100 child with clinical and laboratory evidence of pneumonia ranging from one month to three years and Group (II) Control group: Includes 100 child apparently healthy control who attended for non chest problem or serious medical condition. Serum sodium levels, hemoglobin levels, platelet count, total leucocyte count, and C-reactive protein were done to all children. Results: Hyponatremia was present in 82% of patients with CAP (82 out of 100). Serum level of sodium was significantly lower in children with pneumonia than healthy control (132.08 ± 4.18 vs 139.42± 2.57). There was a statistically significant negative correlation between the grade of respiratory distress and the level of serum sodium (p <0.001). Conclusion: hyponatremia is common among hospitalized children with CAP. Serum sodium levels are lower in children with pneumonia than matched healthy controls.