The aim of this study was to evaluate a trauma-adapted intervention for survivors of interpersonal violence that combines psychoeducation and specific mindfulness-based exercises developed for patients with posttraumatic stress disorder (PTSD) with formal practices from mindfulness-based stress reduction and loving-kindness meditation. Fourteen patients with PTSD after interpersonal violence participated in eight treatment sessions. The intervention was evaluated in a nonconcurrent multiple-baseline across-individuals design. From baseline (2, 3, and 4 weeks, randomly assigned) until 8 weeks after the intervention, self-reported PTSD symptoms and well-being were measured on a weekly basis. The intervention was further assessed through self-ratings and the Clinician-Administered PTSD Scale (CAPS-5) administered prior to treatment, immediately after treatment and at a 6-week follow-up. Tau-U analyses showed for the majority of the 12 completers a significant reduction of PTSD symptoms and a significant increase in well-being. Furthermore, we found large effects on PTSD symptoms as measured by the CAPS-5 (Hedges’ g = 1.66), as well as on depression (Hedges’ g = 1.08) and psychological distress (Hedges’ g = 0.85), complemented by relevant increases in mindfulness skills and self-compassion. This study contributes evidence that mindfulness and loving-kindness are useful for reducing PTSD in victims of interpersonal violence, especially when the intervention is tailored to the specific needs of these patients.