Objective: Among the most prevalent and distressing concerns endorsed by breast cancer survivors is fear of cancer recurrence (FOR), and one of the most salient facets is the worry that a recurrence of cancer could cause one's death. The primary goal of the present study was to test the effects of a brief, low-cost gratitude intervention on overall FOR and death-related FOR, positing pursuit of meaningful goals as a theoretically driven putative mediator. To replicate published tests of similar gratitude-eliciting interventions, positive affect (PA) was also considered as an outcome. Method: Sixty-seven women with early stage breast cancer were randomly assigned to either a 6-week online gratitude intervention or a 6-week online control condition. Outcomes were assessed at pre- and posttreatment, as well as 1 month and 3 months after the end of treatment. The mediator, meaningful goal pursuit, was measured via assessments over the 6-week intervention period. Results: Results revealed that patients in the gratitude intervention experienced a significant decrease in death-related FOR compared to the control condition. Moreover, this effect was significantly mediated by meaningful goal pursuit (and not by PA). The gratitude intervention was also found to prevent declines in PA observed in the control condition. Conclusions: Overall, findings support the notion that a brief gratitude intervention can promote well-being and psychological adaptation to cancer by stimulating the pursuit of meaningful goals and subsequently reducing death-related FOR.