Participatory surveillance refers to the practice of individuals voluntarily and actively engaging in the collection, sharing, and analysis of data related to health that can be used for monitoring trends or identifying events. This is commonly facilitated through digital platforms, apps, or online tools. Unlike traditional surveillance that is top-down (e.g., government-led health monitoring), participatory surveillance is driven by the community or individuals. Platforms like Outbreak Near Me (used in the US) or InfluenzaNet (used in Europe) allow individuals to self-report symptoms, contributing to early detection and mapping of disease spread. Participatory surveillance can complement official sentinel-based surveillance for diseases such as influenza, COVID-19 or Respiratory Synctyial Virus by providing information directly from individuals who are experiencing symptoms but are not seeking healthcare. With over 15 years of history, participatory surveillance has proven to be a crucial public health tool that combines technology and people’s active participation.