This study examined a gratitude intervention repeating Emmons and McCullough study (2003) in a Spanish sample. Participants were randomly assigned to one of three conditions (gratitude, hassles and any event) and kept daily records during 2 weeks of gratitude, affect, quality of relationships, physical and subjective well-being. We added design features to assess the intervention long-term impact (follow-up measures), and to improve the design control (pre-treatment measures). Following the cited authors' analysis, i.e., comparing groups only in the post-test, we replicated their results, finding differences in positive affect and gratitude between the gratitude condition and the hassles condition. However, when including both the pre and the follow-up measures in the analysis, results were replicated only partially, as the difference in gratitude disappeared. Moreover, the difference in positive affect between groups in the post-test seemed to be influenced mainly by a decrease in positive affect in the hassles group. Post-test differences between groups in positive affect disappeared in the follow-up. Gratitude interventions may have an effect on well-being, but we consider other methods to promote gratitude besides gratitude journals should be tested.