Background: Sudden cardiac death (SCD) is a major health problem in the United States, causing approximately 300,000 to 400,000 deaths annually. Adolescents who have implantable cardioverter defibrillators (ICDs) or pacemakers due to arrhythmias have increased risk of SCD and face unique challenges that can cause psychosocial distress. Psychosocial interventions are effective for adults with cardiac devices and could positively impact adolescents' adjustment to these devices. It is crucial to establish the feasibility and efficacy of psychosocial interventions in this population. Purpose: This study examines the feasibility of a Mindfulness Based Stress Reduction (MBSR) program for adolescents with ICDs/pacemakers and evaluates anxiety, depression, and coping before and after the six week intervention. Methods: The MBSR intervention was evaluated in a one group pre-post prospective study. Participants' coping (Response to Stress Questionnaire) and anxiety and depression (Hospital Anxiety and Depression Scale) were assessed before and after the MBSR intervention. Qualitative data were obtained from post intervention interviews. Ten adolescent patients with either an ICD or pacemaker who are followed in the cardiology clinic at Children's National Medical Center in Washington, D.C. participated in the intervention. Hypotheses were tested with paired-sample t-tests, Pearson's correlations and Fisher's exact tests. Results: Feasibility was demonstrated by successful recruitment of 10 participants, 100% participation, and 100% completion. Anxiety decreased significantly following the 6-week MBSR intervention, with a large effect size. Coping skills were related negatively to anxiety and depression. Conclusion: The small but growing research literature on MBSR interventions in adolescents supports a positive effect on anxiety, depression, and coping. This study verifies the efficacy and tolerability of an MBSR intervention in a population of adolescents previously unexamined in the research literature, adolescents with ICDs/pacemakers. This study provides clinicians and researchers with specific data about types of coping strategies and their relationships to anxiety and depression. Due to the small sample size, it will be difficult to generalize the findings without additional research. This study will pave the way for larger, more rigorous studies to further examine the efficacy of MBSR interventions in adolescents with high risk cardiac diagnoses.