Prominent models and interventions designed to promote forgiveness have distinguished one's decision to forgive from achieving forgiveness as an end state, but because of a lack of a strong measure, there is a weak research base on making a decision to forgive. Thus, in three studies, the authors developed the Decision to Forgive Scale (DTFS) and examined evidence for its reliability and construct validity. The article focused on distinguishing making a decision to forgive from achieved level of forgiveness. Scores on the DTFS showed evidence of reliability, with Cronbach's alpha coefficients ranging from .92 to .94, and a 1-week temporal stability coefficient of .68. Using several strategies, the authors demonstrated that the DTFS is empirically distinct from the Transgression-Related Interpersonal Motivations scale (TRIM; McCullough et al., 1998). Namely, a 3-factor confirmatory factor analysis that included the DTFS and the 2 TRIM subscales showed excellent fit, suggesting these instruments assess 3 different constructs. The DTFS was only moderately related to the TRIM subscales, was more strongly related to stage of change than the TRIM, and predicted subsequent TRIM scores in a cross-lagged model. Finally, although decisions to forgive generally suggested greater forgiveness, these constructs interacted to predict existential distress. Namely, as decisional forgiveness increased, revenge was more strongly related to existential distress. Overall, the DTFS shows considerable promise for further clinical and basic research applications.