Youth smoking is an important target for public policy. The implicit assumption behind targeting youth is that policies that reduce youth smoking initiation will reduce lifetime smoking propensities. This assumption has never been tested empirically. I use data from the National Longitudinal Survey of Youth (NLSY) to follow the smoking pattern of one cohort of teenagers. I examine how smoking rates in youth and young adulthood are affected by the taxes individuals faced at age 14. In panel data analysis, I find that the effects of taxes at age 14 are considerably attenuated by adulthood. I find some evidence suggesting that this result is a consequence of delayed smoking initiation that is correlated with taxes. These results suggest that reducing smoking among teens through tax policy may not be sufficient to substantially reduce smoking in adulthood.