Romantic attachment orientations are important predictors of individuals’ and their partners’ well-being and health. However, less is known about whether similarity in attachment between partners predicts better well-being and health outcomes. In two studies (total N couples = 1,602), we tested with actor-partner interdependence and dyadic polynomial regression models if partners’ attachment and their similarity were linked to their well-being and health (i.e., life satisfaction, depressive symptoms, self-rated health, medical conditions). Results revealed significant actor effects between anxiety and life satisfaction (Study 1, male partners Study 2), depressive symptoms (both studies), self-rated health (both studies), and medical conditions (Study 2 only). For avoidance, significant actor effects were found for life satisfaction (Study 1, female partners Study 2), depressive symptoms (both studies), and self-rated health (both studies). Partner effects emerged for anxiety and life satisfaction (Study 1, male partners Study 2) and depressive symptoms (Study 1 only) and for avoidance and life satisfaction (Study 1, male partners Study 2), depressive symptoms (both studies), and self-rated health (both studies). The results of dyadic polynomial regression and response surface analyses, however, provided no evidence for any similarity effects of romantic attachment on well-being and health in both studies. In sum, the findings suggest that lower anxiety and avoidance in both partners is generally associated with higher well-being and health. However, similarity in partners’ attachment seem unimportant for concurrent well-being and health. Implications of the findings are discussed considering attachment theories and relationship processes.