Two experiments extended terror management theory to investigate forgiveness in close relationships. We hypothesized that mortality salience would elicit less forgiveness in less committed relationships. In Experiment 1, participants were primed with either mortality salience or a physical pain control condition, recalled a recent hurtful interpersonal offense, and reported their degree of forgiveness. Mortality salience evoked less forgiveness in less committed relationships. In Experiment 2, participants were assigned to recall an offense that occurred in a low‐commitment or high‐commitment relationship. Again, mortality salience elicited less forgiveness in less committed relationships; it elicited more forgiveness in more committed relationships. Moreover, this interaction was mediated by empathy. Existential considerations may play an important role in the functioning of close relationships.