Background: Insecurity has characterized the Eastern regions of the Democratic Republic of Congo for decades. Providing health services to sustain women's and children's health during protracted conflict is challenging. This mixed-methods case study aimed to describe how reproductive, maternal, newborn, child, adolescent health and nutrition (RMNCAH+N) services have been offered in North and South Kivu since 2000 and how successful they were. Methods: We conducted a case study using a desk review of publicly available literature, secondary analysis of survey and health information system data, and primary qualitative interviews. The qualitative component provides insights on factors shaping RMNCAH+N design and implementation. We conducted 49 interviews with government officials, humanitarian agency staff and facility-based healthcare providers, and focus group discussions with community health workers in four health zones (Minova, Walungu, Ruanguba, Mweso). We applied framework analysis to investigate key themes across informants. The quantitative component used secondary data from nationwide surveys and the national health facility information system to estimate coverage of RMNCAH+N interventions at provincial and sub-provincial level. The association between insecurity on service provision was examined with random effects generalized least square models using health facility data from South Kivu.