The terror management health model suggests targeting sources of self-esteem or identity, in conjunction with mortality salience, offers a pathway for health behavior promotion. To date, however, experimental evidence has been limited to single time point studies. Two studies assessed whether similar processes impact behavior over time. In Study 1, mortality salience was paired with exercise (i.e., riding a recumbent bike); two weeks later, individuals primed with mortality reported more exercise than those not primed with death, and this increased fitness-contingent self-esteem and exercise intentions. In Study 2, when smokers visualized a prototypical unhealthy (vs. typical) smoker after mortality salience, they reported more attempts to quit smoking (over three weeks) than participants not primed with mortality. This facilitated continued quit attempts and decreased smoker identification three weeks later. Implications are discussed for a longitudinal process model in which mortality salience catalyzes a reinforcing relationship between behavior and esteem/identity, potentially sustaining health behavior change over time.