objectives: to assess the economic impact of a 100% smoke-free law on bars and restaurants in an argentinean province. materials and methods: we conducted a time series analysis of restaurant and bar revenues in the province of santa fe 31 months before and 29 months after the implementation of the 100% smokefree environment law. the neighboring province of entre rios without smoking restrictions at the time of this study, was used as the control province. results: average taxable revenues post-legislation in the province of santa fe as a whole and in the two most important cities were higher when compared to the total provincial revenue pre-legislation. no significant differences were observed with the total revenue from the province of entre rios. conclusions: we found no statistically significant evidence that the 100% smoke-free environment legislation in the province of santa fe, argentina, had a negative impact on the revenues of local bars and restaurants.