Emotionally focused couple therapy (EFT; Johnson, The practice of emotionally focused couple therapy (1st/2nd edition). Brunner-Routledge, New York, 2004) is an effective treatment of relationship distress (Johnson et al., Clinical Psychology: Science and Practice, 1999; 6, 67). However, less is known about EFT's impact on couples' relationship-specific attachment bond. Using hierarchical linear modeling with a sample of 32 couples, we examined session-by-session changes in couples' relationship-specific attachment anxiety and avoidance and pre- to posttherapy changes in their relationship-specific attachment behaviors. Couples significantly decreased in relationship-specific attachment avoidance, and those who completed a blamer softening significantly decreased in relationship-specific attachment anxiety. Couples' attachment behavior significantly increased toward security. Finally, session-by-session decreases in relationship-specific attachment anxiety and avoidance were significant associated with increases in relationship satisfaction across sessions. These results provide empirical support for the attachment-based assumptions of EFT.