Background: Community-acquired pneumonia (CAP) plays a crucial role in under-five children's morbidity and mortality. The impact of CAP became more evident in Upper Egypt societies and has placed a substantial burden on already overburdened health and community services. Data on how CAP risk factors interact would be of great value and it could be addressed through preventive programs implemented to serve under-five children. Objective: This study identified the determinants for CAP in under-five children admitted to Aswan University Hospital. Method: A hospital-based, case-control study involving cases of pneumonia among children aged 2–59 months was conducted from August 1st, 2019 to August 31st, 2020 at Aswan University Hospital, Egypt. The controls consisted of children admitted to the outpatient clinic in the same hospital for elective surgery. Children with any comorbidities were excluded. A multivariable regression analysis was performed including variables that were significant at p <0.05 in the bivariate analysis. Results: The study evaluated 160 children in the case group and 160 children in the control group. Underweight (OR=17.18, 95% CI=4.35-37.64), current parental smoking (OR=9.54, 95% CI=2.80-32.41), mothers' knowledge score about CAP (moderate knowledge OR= 2.23, 95% CI=1.25-9.46, poor knowledge OR=6.11, 95% CI=1.46-8.08) and when the distance to the nearest health center > 5 kilometers (OR=4.70, 95% CI=1.3-16.24) were the significant predictors for CAP. Conclusion: Higher risk for progressing community-acquired pneumonia is associated with underweight, current parental smoking, poor score knowledge of mothers regarding CAP, and being at a distance > 5 kilometers from the home to the closest health center.