Large discrepancies between people`s intention to travel and actual tourism behavior indicate that intention is not a sufficient instigator for tourism behavior. To explore this intention-behavior gap the present study employed a prospective design: TPB variables and action planning were assessed at baseline and actual tourism behavior was assessed 6 months later. Positive moderating effects of action planning were demonstrated for tourism behavior, indicating that people with high level of action planning are significantly more likely to translate their intentions into actual tourism behavior. Intention partially mediated attitude(perceived behavioral control)-behavior relationships and fully mediated subjective norm-behavior relationship. Action planning moderated the mediation process(moderated mediation): The strength of the mediated effect increased along with levels of action planning. For intentions to mediate the attitude(subjective norm, perceived behavioral control)-behavior relationships, people must hold sufficiently high levels of action planning.