Background: In sub-Saharan Africa, the DRC ranks among countries with high infant mortality. To solve this problem, the Health Ministry has set up a programme: the use of integrated management childhood illness (IMCI) in community care sites (CCSs) managed by non-health professional persons known as community health workers (CHW). This approach has not yet been integrated into the health pyramid. This is why we chose the Realist Evaluation Approach to evaluate the effectiveness of this programme on Universal Access to care for children under 5 years of age in the DRC. Methods/design: To conduct this exploratory study which is essentially a descriptive case study, we applied the principles of a realist evaluation by context-mechanisms-effects explained in the conceptual framework. The preliminary theory of the programme was elaborated by data collection through a literature review coupled with semi-structured interviews with key informants who were managers of the government programme and technical and financial partners of the programme. Results: IMCI has been evaluated and shown its positive contribution in the reduction of global children mortality. In the DRC, summaries of data collection through a literature review coupled with semi-structured interviews showed the same result. However, under criticism, based on the data collected during this exploratory study, it is promisingly apparent that this programme will achieve the objectives assigned to it through the preliminary theory of the programme. Conclusion: The literature review corroborated the effectiveness of the IMCI