The characteristics of dispositional mindfulness have rarely been explored in unhealthy populations. We sought to evaluate its association(s) with psychological morbidity and disease severity in 30 outpatients with implantable cardioverter defibrillators naïve to mindfulness training. We used the Five Facets of Mindfulness and the Hospital Anxiety and Depression Scale to measure dispositional mindfulness and anxiety/depression, respectively. Associations were estimated using linear regression models. Higher dispositional mindfulness was observed in patients with lower anxiety scores (β = - 1.10, CI: -1.71, -0.49) and no history of depression (β = - 7.95; CI: -14.31, -1.6) by univariate analysis. No associations were observed with disease severity or other covariates. In conclusion, psychological well-being and psychological morbidity, and not disease severity, appear to be associated with dispositional mindfulness in patients with implantable cardioverter defibrillators. Further research is needed to confirm these findings.