Whereas some data are available about late smoking relapse among adult quitters, there are none for teen quitters. This study is a 6-year follow-up of teen quitters (n = 253) for whom we collected (retrospectively) data on the extent and timing of relapse. We found that even after a strictly defined quit (six-months prolonged abstinence) at one year, substantial relapse occurred both early and late: the majority (55%) of relapses occurred after the 0-1 year interval after having quit. These findings have implication for the need for research into the relapse process for teen quitters, and for the need to develop interventions for teens (as for adults) to prevent (early and) late relapse. (C) 2016 Published by Elsevier Ltd.