Objective: To estimate the prevalence and risk of asthma by occupational sector among artisans and merchants enrolled in the Social Security Scheme for the Self-Employed (RSI). Method: The RSI extracted data covering all of its insured individuals who received at least one reimbursement for an anti-asthma medication between 2010 and 2012. This dataset also included the insured individuals’ current sector of activity, coded according to the French classification of economic activities. By applying a validated predictive model to these data to identify individuals with asthma, we estimated: the prevalence of current asthma among RSI artisans/merchants by sector of activity; the risk of asthma (odds ratios [OR] and 95% confidence interval [95% CI]) in each sector compared to all other sectors. Results: The study included 967,391 artisans and merchants (74% men and 26% women). The estimated overall prevalence of current asthma was 5.9%. It was 5.6% among men and 7.0% among women. Among men, elevated risks were observed in the following sectors: "food industry" (OR = 1.70 [95% CI 1.63–1.78]), "recycling" (OR = 1.44 [95% CI 1.23–1.70]), “health and social work” (OR = 1.34 [95% CI 1.16–1.54]), and “land transport” (OR = 1.08 [95% CI 1.03–1.13]). Among women, elevated risks were observed in the "education" sector (OR = 1.27 [95% CI 1.08–1.50]), "medical equipment manufacturing" (OR = 1.25 [95% CI 0.99–1.58]), "land transport" (OR = 1.11 [95% CI 0.98–1.25]), and "hotels/restaurants" (OR = 1.10 [95% CI 1.05–1.15]). Discussion: The estimated prevalence of asthma among artisans and merchants in the RSI is close to that estimated in the general French population. Significant risks of asthma are evident in sectors known to be high-risk, but also in sectors where this risk had not previously been identified. (R.A.)