Résumé : Aim: To describe health care expenditure levels, distributions and main drivers, and to investigate whether incurring excessive expenditure is associated with a series of demand- and supply-side factors. Method: As part of a quasi-experimental evaluation to assess the impact of a DFID-funded health systems strengthening project in DRC, a baseline population-based household survey was conducted in four provinces in 2014. Data included type, level and utilization of healthcare services, accessibility to care, patient satisfaction and disaggregated expenditure. Multivariate logistic regressions of excessive expenditure for outpatient care – set at various thresholds such as greater than double the median expenditure – were performed to explore incidence and predictors of atypically high expenditure incurred by individuals.Findings: Of 3,341 individuals, 65.6% of those reporting an illness in the past four weeks sought outpatient care with an average of 1.1 visit per episode of illness. Overall mean expenditure per visit was US$6.7 (SD=10.4) with 29.4% incurring excessive expenditure. Main predictors of excessive expenditure included utilizing public services offering the complementary benefit package, expenditure composition, severity of illness, residence and wealth (p<.05).Conclusion: With limited cost-sharing mechanisms available, burdensome expenditure for health is a health financing challenge. The current Congolese reform should learn from expenditure studies.