Background <p>Event-Based Surveillance (EBS) collects signal information from communities and other sources to improve the early detection and response to outbreaks or other public health threats. With the ongoing conflict in Sudan, a major disruption has posed to the health services including Indicator-Based Surveillance (IBS), and EBS has become particularly imperative during this challenging time. This article documents the experience of EBS implementation in Sudan, highlights the practical measures to keep EBS functioning in responding to the evolving war, and shares the lessons learned.</p> Methods <p>A descriptive qualitative synthesis and desk review of the EBS project aggregated reports, tools, and documents were carried out. Data were organized into themes and analyzed manually using a thematic analysis, paying particular attention to the best practices in the development of EBS, innovations, challenges, and lessons learned.</p> Results <p>EBS in Sudan has successfully established and sustained a network of community volunteers nationwide. The EBS unit collaborated with partners and implemented many innovative ideas to train and communicate with the EBS focal persons at the state level and community volunteers during the conflict. Data and information generated by the system were integrated with the IBS data and used for decision-making at the Emergency Operating Centre (EOC). The drivers for success include careful selection of volunteers, addressing their needs, and maintaining communication with them.</p> Conclusions <p>Despite the limited resources and the current war, the system kept functioning, and its core activities were maintained. The commitment of both partners and the Government of Sudan is an asset that should be strategically leveraged to expand this surveillance to areas that can benefit from EBS the most.</p> Graphical abstract <p></p>