Objective: to describe the voluntary adoption of smoke-free homes in Spain among general population and to identify variables associated with its voluntary adoption. Methods: cross-sectional study of a representative sample (n=731) of the adult population (>26 years) of Barcelona, Spain, in 2013-2014. We defined smoking rules inside the households as complete indoor rules (when smoking was not allowed inside the house), and partial or absent indoor rules (when smoking was allowed in some designated places inside the house or when smoking was allowed everywhere) and described them according to the perceived risk of the secondhand smoke (SHS) exposure. We calculated the prevalence and prevalence ratios (PR) according to sociodemographic variables. Results: 57.4% of households had complete indoor smoke-free rules. The prevalence of households with complete indoor rules was higher among women (PRa: 1.15; 95% CI 1.00 to 1.33), married (PRa: 1.18; 95% CI 1.01 to 1.38), never-smokers (PRa: 2.68; 95% CI 2.06 to 3.50) and in households where a minor lived (PRa: 1.40; 95% CI: 1.20-1.65). Believe that breathing tobacco smoke from smokers is dangerous for non-smokers (PRa: 1.77; 95% CI: 1.06-2.97) is associated with the voluntary adoption of complete indoor smoke-free home. Conclusions: risk perceptions of SHS exposure were associated with the voluntary adoption of indoor smoke-free homes.