Pediatric infectious diseases remain a major cause of morbidity and mortality in developing countries despite significant advances in medical science, vaccination programs, and public health interventions. Children in low- and middle-income countries face a disproportionately high burden of infectious diseases due to poverty, malnutrition, inadequate sanitation, limited healthcare access, overcrowding, and emerging antimicrobial resistance. Common pediatric infectious diseases include acute respiratory infections, diarrheal diseases, malaria, tuberculosis, measles, dengue fever, HIV/AIDS, and neglected tropical diseases. These conditions contribute significantly to childhood mortality, impaired growth, developmental delays, and economic burdens on families and healthcare systems. This review examines the epidemiology, risk factors, clinical manifestations, diagnostic approaches, management strategies, prevention measures, and future challenges related to pediatric infectious diseases in developing countries. The findings emphasize the importance of integrated healthcare systems, vaccination, nutrition programs, antimicrobial stewardship, and global health collaborations in reducing childhood infectious disease burdens.