BACKGROUND: The aim of this study is to assess the impact of the Spanish tobacco control legislation on smoking behavior and salivary cotinine concentration among smokers. METHODS: We used data from a longitudinal study, before (2004-2005) and after (2013-2014) the implementation of the two national smoking bans (in 2006 and 2011), in a representative sample of adults (≥16 years old) from Barcelona (Spain). We only analyzed a subsample of continuing smokers (n = 116). We conducted a survey on smoking behavior and obtained saliva sample for cotinine analyses. For this report, we analyzed a subsample of continuing smokers (n = 116). We calculated geometric means (GM). RESULTS: Among continuing smokers, salivary cotinine concentration significantly increased by 28.7% (GM from 91.7 ng/ml to 117.3 ng/ml, p = 0.015) after the implementation of the two Spanish smoke-free bans. Nonetheless, no pattern of change was observed in the self-reported number of cigarettes smoked daily. CONCLUSIONS: Our study shows a significant increase in the salivary cotinine concentration among adult continuing smokers after both Spanish legislations. This increase could be due to differences in smoking topography (increase in the depth of inhalation when smoking) along with changes in the type of tobacco smoked (increase in smoking roll-your-own cigarettes or mixed use of roll-your-own and manufactured cigarettes). Our results suggest the need to extend tobacco control policies, focusing on the reduction of use of any type of tobacco product and implementing better treatment to help smokers stop smoking.