Individual differences in attachment are well established as a correlate of couple relationship satisfaction. However, less is known about the role of attachment in predicting satisfaction at specific milestone points in couple relationships. The present study explored the role of attachment in predicting relationship satisfaction during couples’ first pregnancy, and the mediating role of relationship enhancing behaviors. Male and female attachment anxiety and avoidance predicted their own low relationship satisfaction, and this was partially mediated by relationship enhancing behaviors. Male attachment anxiety and avoidance predicted low female satisfaction, and this was fully mediated by relationship enhancing behaviors. This study is the first to highlight the important role of male attachment during pregnancy, and the mediating role of relationship enhancing behaviors.