Capitalization interactions, in which partners share positive events, typically produce positive relationship outcomes (Gable, Gonzaga, & Strachman, 2006). However, the limiting conditions of these interactions have not been examined. In this study, 101 dating couples discussed a positive event in the life of each partner. Ratings of perceived responsiveness were made by both the romantic partner who disclosed a positive event and his/her responding partner. Trained observers then rated each videotaped interaction. More avoidantly attached responders reported being and were rated by coders as less responsive, particularly if their disclosing partners were more anxiously attached. Avoidantly attached individuals also underestimated their partners' responsiveness relative to observer ratings. Anxious responders underestimated their own responsiveness when their disclosing partners were more avoidantly attached. These results indicate that insecurely attached individuals are relatively less likely to be responsive and to perceive responsiveness in capitalization interactions than are more securely attached individuals. This is especially true when highly anxious and highly avoidant individuals are relationship partners.