Strengthening disease surveillance systems in France requires greater involvement of general practitioners (GPs). Methods—A descriptive, cross-sectional survey was conducted across four regions: Auvergne, Brittany, Provence-Alpes-Côte d'Azur, and Rhône-Alpes. The identified networks were the Inserm Sentinelles network, the Grogs (Regional Influenza Surveillance Groups), the General Practice Observatory, and the Saint-Étienne city network. The objective was to identify the determinants of GPs’ participation and non-participation in health surveillance networks in 2008 across these four regions of France. Results - A total of 306 physicians were surveyed: 150 active participants in a network and 156 non-participants. Participating GPs were more often involved in activities outside their professional practice and made greater use of computer tools. Physicians participating in a surveillance network cited information exchange, the promotion of general practice, and the improvement of their practices as motivations. Non-participating physicians cited lack of time, not being invited to participate, and unfamiliarity with the networks as obstacles. Conclusion - Broader information and more active outreach by the networks could serve as levers to promote the recruitment of GPs. (R.A.)