The French Institute for Public Health Surveillance, in partnership with the University of Bordeaux II, the University of Toulouse III, and the Medical Inspectorate, conducted a pilot project aimed at estimating the prevalence of asthma by industry sector and occupation among employees monitored by a network of volunteer occupational physicians in two regions (Aquitaine and Midi-Pyrénées). Data were collected during occupational health visits with randomly selected employees using standardized questionnaires. A total of 110 occupational physicians participated in the pilot study, which included 6,906 employees between 2007 and 2008. Two asthma indicators were used: "current asthma," defined as reporting an asthma attack in the past twelve months and/or current treatment for asthma; and "lifetime asthma," defined as a positive response to the question "Have you ever had asthma?" Industry sector and socio-professional category (PCS) were collected for current employment. The prevalence of current asthma was 5.4% (95% CI [4.9–5.9]) in the sample. The risk of having current asthma was significantly higher in the “health and social services” sector (OR=1.4; 95% CI [1.0–1.9], prevalence 6.5%) and in the occupational category “civil servants and public service employees” (OR = 1.5, 95% CI [1.1–1.9], prevalence 8.9%). The lifetime prevalence of asthma was 11.1% (95% CI [10.3–11.8]) in the sample. The risk of having lifelong asthma was significantly higher in the "IT activities" sector (OR=1.8; 95% CI [1.0–3.0]) and in the occupational category "civil servants and public service employees" (OR=1.6; 95% CI [1.1–2.2], prevalence 13.0%). If surveillance were to continue through a network of occupational physicians, it could be considered to expand it to other regions to include a large number of employees or to conduct targeted asthma surveillance in sectors and occupations that expose workers to asthma-inducing hazards. (R.A.)