Background and Purpose: The implantable cardioverter (ICD) is the mainstay of treatment for patients at risk for and those who have had life threatening arrhythmias. The negative emotional responses are important for clinicians to identify. The purpose of this study was to develop and evaluate the psychometric properties of The Emotional Responses Post Implantable Cardioverter Defibrillator Scale among patients with ICD. Methods: This study was completed in phases; content validity, construct validity, internal consistency, reliability of the instrument and test-retest reliability. Results: The 3 factors are Factor 1, Depressive Symptoms; Factor 2, Anxiety Symptoms; and Factor 3, Fear of the Device. The overall coefficient for the total set of items was .85. Coefficients of the three factors ranged from .80 to .85. Conclusion: This study provides evidence to support the content, construct validity, and reliability of this scale.