Introduction: delay in seeking healthcare contributes significantly to under-five mortality. Multiple socioeconomic and demographic factors have been reported as predictors of such delay. There is no published research in this area in Rwanda. Our aim was to describe the caregivers' delay in seeking healthcare during the acute phase of a childhood illness among under-five children admitted in a tertiary hospital, Rwanda.

Methods: this was an analytical, descriptive cross-sectional study conducted at University Teaching Hospital of Kigali. Bivariate analysis and logistic multivariate regression were used to analyze factors associated with delayed care-seeking behavior, defined as seeking care after the first 48 hours of illness onset.

Results: among 275 admitted children under age five, care-seeking delay occurred in 35% (97/275) of cases. The most significant predictors of delay in seeking care were use of traditional healers (AOR = 14.87, 95% CI: 3.94-56.12), the recognition of illness as mild (AOR = 8.20, 95% CI: 4.08-16.47), use of un-prescribed medicine at home (AOR = 2.00, 95% CI: 1.01-3.91), use of special prayers provided by ministers of God before seeking healthcare (AOR = 6.42, 95% CI: 2.50, 16.48), and first consultation at public institutions (AOR = 4.00, 95% CI:1.54-10.39).

Conclusion: even though Rwanda has made tremendous achievements in strengthening the community-based health systems, delayed care-seeking is a reality. Health education and behavior change communication interventions are needed at the community level to address the factors that lead to delay in seeking healthcare.