Background: Community-acquired pneumonia (CAP) is widely acknowledged as the leading cause of morbidity and mortality among children worldwide, particularly in developing nations. Children with congenital heart disorders (CHD) are more likely to have pneumonia and require repeated hospitalization.

Aim of the study : To determine the most frequent microorganism responsible for pneumonia in children with and without CHD, as well as the prevalence of bacteremia in such cases, and whether or not CHD raises the risk of bacteremia in children with pneumonia.

Patients and methods: We conducted our prospective cohort study in Department of Pediatrics, Faculty of Medicine, Zagazig University on 50 children who divided equally into group I contained children with pneumonia. GroupII contained children with pneumonia and CHD. All underwent CBC, CXR, ECHO , sputum culture ,blood culture .

Results: Among the children in group I who had both pneumonia and CHD, the blood culture results revealed no growth in 15 cases (60%),and klebsiella pneumoniae in 3 cases(12and there was not a statistically significant differance between both groups.

Conclusion: Klebsiella pneumoniae was the most prevalent pathogen responsible for pneumonia in children with and without congenital heart diseases, and linezolid was the most sensitive antibiotic. In children who have pneumonia, congenital cardiac diseases did not raise the risk of bacteremia.