Abstract: Deployment-related PTSD can negatively impact social functioning in veteran families. Individualized PTSD-focused therapy does not consistently lead to improved social functioning. Addressing social difficulties more directly in these families is thus important. The goal of this study was to conduct an observational pilot of the clinical effectiveness of after deployment adaptive parenting tools (ADAPT), a parenting intervention for veterans and their partners. Participants were recruited at Psychotrauma Center South Netherlands of Reinier van Arkel, an institute of psychiatric care in The Netherlands. Social functioning (family functioning, parent reported child functioning, parental attachment) was assessed at baseline, 4-month post-baseline (end-of-treatment), and 10-month post-baseline. Veteran outcomes in ADAPT were compared with outcomes for veterans undergoing treatment as usual (TAU) consisting of individualized PTSD treatment. Emotion regulation and mentalization were tested as possible mediators of effect. Results showed a direct and sustained reduction in perceived posttreatment family dysfunction in veterans, and preliminary evidence of a decrease in perceived family dysfunction in partners at 10-month post-baseline. Although veterans in both ADAPT and TAU groups received PTSD therapy and reported a reduction in PTSD symptoms, only the ADAPT group showed enhanced family functioning. No significant effects were found on child functioning and parental attachment. No mediation effects were found for emotion regulation and mentalization. Low statistical power may explain the lack of significant findings. This study provides initial evidence of ADAPT's clinical effectiveness in improving family functioning, yet future research should examine the mediating processes, preferably using longer time frames with more follow-up measurements.