Abstract: Objective: This study evaluates the feasibility and acceptability of delivering Mindful Self-Compassion (MSC) to veterans with moral injury and co-occurring PTSD and substance use disorder (PTSD-SUD). Methods: Veterans (N = 26; M age = 50.92; 100% male) were recruited for an 8-week MSC group. Participants completed measures of self-compassion, guilt, shame, PTSD, and substance use outcomes at baseline, post-treatment, and one-month post-treatment. Results: The recruitment target was easily met, and dropout rates were low (30.8%) for a comorbid veteran sample. Participants reported satisfaction with the intervention. Clinically meaningful change was examined for self-compassion, trauma-related symptoms, and substance use. A clinically meaningful increase for self-compassion and clinically meaningful decreases in PTSD symptoms, guilt, shame, and number of drinking days were observed. Conclusions: The open-label design and small sample size preclude conclusions regarding efficacy. However, these preliminary findings are encouraging and suggest further investigation of MSC as a compliment to existing trauma-related therapies (NCT03681288).