Epidemiological information on influenza comes from multiple sources. Participatory surveillance for influenza and influenza-like illness (ILI) is one approach for gathering information from the community to monitor trends in influenza, while also helping to inform other important public health issues. The approach should be considered to be complementary to other sources of influenza surveillance information. One advantage of participatory surveillance is that information comes from both asymptomatic and symptomatic individuals, and from symptomatic individuals who may not initially seek health care. Information may also come from members of the population who may be underrepresented in traditional facility-based surveillance. Where participatory surveillance for influenza and ILI has been implemented experience indicates that such systems are accurate, flexible, cost-effective and robust with regard to changes in health care seeking behaviour. However, there are also a number of limitations, challenges and biases that must be taken into consideration. This WHO document provides globally applicable guidance on implementing participatory surveillance for influenza and ILI based on expert input and abundant experience from countries in which such surveillance has been implemented. The document sets out best practices for public health officials to consider, either when looking to implement a participatory surveillance system or when making changes to an existing system.