Introduction A mindfulness intervention is a mind-body complementary health approach that focuses on the relationships between mind, body, brain, and behavior. Mindfulness-Based Stress Reduction (MBSR) and similar mindfulness programs have been shown to decrease drug craving and relapse and improve emotional regulation, stress, pain, and anxiety. To our knowledge, a very limited number of studies have examined its efficacy in individuals from underserved populations.Underservedpopulations experience disparities in healthcare access, and as a result, see poorer addiction-related outcomes.The goal of this pilot study was to utilize an evidence-based, neuroscience-informed brief mindfulness intervention to improve mental health and decrease substance use behavior in a vulnerable, underserved population in New Jersey suffering from opioid use disorder (OUD). Methods Weimplemented a brief MBSR intervention in 15 underserved individuals undergoing inpatient medication-assisted treatment (MAT) for OUD.Individuals received weekly intervention sessions lasting one hour over six weeks.Furthermore, they practiced mindfulness for 10 minutes daily.Participants completedpre-and post-mindfulness intervention surveys to examine their mental well-being, drug craving, perceived stress, and emotional regulation. Results Within-subjects t-test results showed that compared to pre-intervention, participants showed significantly decreased perceived stress (t(14)=2.401,p=.015) and significantly decreased difficulty in emotional regulation (t(13)=3.426,p=.002 ) at post-intervention.They also showed significantly decreased drug craving post-intervention (t(14)=5.501,p=.<001).Anxiety decreased post-intervention but was not statistically significant (t(14) =1.582,p=.068). Conclusion This pilot study demonstrates that a brief mindfulness intervention can be effective for underserved individuals with OUD.Consistent with our hypothesis, results showed that a six-week mindfulness intervention could reduce everyday stress, drug craving, and difficulties in emotional regulation.In the future, a large-scale randomized control trial should be conducted with a control group to demonstrate the efficacy of this useful intervention.