This paper studies the effect of e-cigarette taxes enacted in seventeen states, Washington D.C., and two large counties on e-cigarette prices, e-cigarette sales, and sales of other tobacco products. E-cigarette taxes are levied in heterogenous ways, and we estimate the effect of standardized e-cigarette taxes using NielsenIQ Retail Scanner data from 2013 to 2019. We find that 91% of e-cigarette taxes are passed on to consumer prices. We then estimate reduced form and instrumental variables regressions to examine the effects of e-cigarette and cigarette taxes and prices on sales. We calculate an e-cigarette own-price elasticity of -2.3, with considerable heterogeneity across e-cigarette flavored and non-flavored products. E-cigarette price elasticities are particularly high for non-mentholated flavored products. Further, we document a cigarette own-price elasticity of -0.4 and positive cross-price elasticities of demand between e-cigarettes and cigarettes, suggesting economic substitution.