We study the impact of school smoking bans on individual health behavior in Germany. Using a multiple difference-in-differences approach combined with randomization inference, we find that the propensity towards smoking reduces by 14-21 percent, while the number of smoked cigarettes per day decreases by 7-25 percent. After elaborating on treatment effect heterogeneity and intensity, we evaluate spillovers to other health behavior of the treated individual and to smoking behavior of non-treated persons living in the same household.