This study examined the trajectories of parents' reflective functioning over the course of individual preparatory sessions with the therapist in attachment-based family therapy (ABFT) for Israeli sexual minority young adults and their nonaccepting parents, and whether such reflective functioning was associated with parents' agreement on the goals for subsequent conjoint corrective attachment sessions. Three parents with good agreement on treatment goals were compared to three parents with poor agreement on treatment goals. Parents' in-session reflectivity regarding their child's experience of nonacceptance, and regarding the quality of their relationship with their child, was observationally measured at the session level. Reflective functioning increased over time among those parents who reported good agreement with the treatment goals. There were no changes in parents' reflective functioning in the poor agreement group. Findings suggest the potential importance of