Background: Theory and research have shown that gratitude interventions have positive outcomes on measures of well-being. Gratitude listing, behavioral expressions, and grateful contemplation are methods of inducing gratitude. While research has examined gratitude listing and behavioral expressions, no study has tested the long-term effects of a gratitude contemplation intervention on well-being. Methods: The present experiment examined the efficacy of a 4-week gratitude contemplation intervention program in improving well-being relative to a memorable events control condition. Pre-test measures of cardiac coherence, trait gratitude, and positive and negative affect were collected. Pre- and post-test measures assessing satisfaction with life and self-esteem were also collected. Daily positive and negative affect were completed twice a week throughout the intervention period. Results: Compared to those in the memorable events condition, participants in the gratitude condition reported higher satisfaction with life and self-esteem. Trait gratitude was found to moderate the effects of the gratitude intervention on satisfaction with life. Conclusion: Grateful contemplation can be used to enhance long-term well-being.