The international response to the evolving Ebola epidemic in eastern Democratic Republic of Congo (DRC) has had interim successes while facing ongoing difficulties. The outbreak has occurred in an area of intractable conflict among multiple armed groups at a time of contentious national elections. Despite porous international borders and considerable population movement, however, transmission has been confined to North Kivu and Ituri provinces. Factors potentially contributing to this containment include conduct of about 55 million screenings, surveillance of contacts (12,591 under surveillance currently), testing of 280 samples per day, provision of safe and dignified burials for most deaths, vaccination of high-risk people (112,485 vaccinated as of May 7, 2019), and medical treatment including four investigational therapies. Major challenges remain. Since late February 2019, a sharp rise in cases and increased transmission have been observed. These coincide with organized attacks by armed groups targeting response teams, deteriorating security, and the population’s increasing distrust of the response effort. The risk of local and regional spread remains high given the high proportion of deaths occurring outside treatment facilities, relatively low proportions of new patients who were known contacts, ongoing nosocomial transmission, and persistent delays in detection and reporting. Stopping this epidemic will require the alignment of the principal political and armed groups in eastern DRC in support of the response.