--- - |2- Abstract Bowlby’s attachment theory describes characteristic patterns of relating to close others and has important implications for psychotherapy. Attachment patterns have been characterized as secure (healthy interdependence with others), anxious (overdependence on others), and avoidant (difficulty relying on others). We update a previous meta‐analysis to determine the association of patient attachment with psychotherapy outcome. Meta‐analysis of 36 studies (3,158 patients) suggested that patients with secure attachment pretreatment show better psychotherapy outcome than insecurely attached patients. Further, improvements in attachment security during therapy may coincide with better treatment outcome. Finally, preliminary moderator analyses suggest that those who experience low pretreatment attachment security may find better treatment outcome in therapy that incorporates a focus on interpersonal interactions and close relationships. The article closes with research limitations, diversity considerations, and therapeutic practices. - Journal of Clinical Psychology, EarlyView.