A smoke-free law went into effect in Spain on 1 January 2006, affecting all enclosed workplaces except hospitality venues, where only partial bans were implemented. The objective was to evaluate the impact of the law among hospitality workers who smoke. The study design is a before-and-after evaluation. We formed a cohort at baseline, during the 3 months before the law went into effect, with 431 hospitality workers (222 smokers). From them, 288 were successfully followed-up 12 months after the ban (118 were smokers at baseline). We analyzed the quit rate, the reduction in the number of cigarettes smoked per day, changes in the Fagerström Test for Nicotine Dependence (FTND) scores, and changes in salivary cotinine concentrations in smokers from baseline to 1 year after the ban. Among 118 smokers, six (5.1%) quit smoking. Among the 112 remaining smokers, the mean number of cigarettes smoked decreased by 8.9% after the ban (from 17.9 to 16.3 cigarettes/day, p < .01). The proportion of workers with a high nicotine dependence (FTND score >6) was reduced by half after the ban (19.5% vs. 9.7%, p = .03). Salivary cotinine decreased by 4.4% after the ban (geometric mean 104.3 vs. 99.7 ng/ml, p = .02). No meaningful differences were found in quit rates and the FTND scores according to type of regulation. The Spanish smoking law has had beneficial effects (reduction in number of cigarettes smoked, cotinine levels, and FTND score) among hospitality workers who smoke.