The first clinical results from the Evaluation of Factors Impacting Clinical Outcome and Cost Effectiveness of the subcutaneous implantable cardioverter defibrillator (EFFORTLESS S-ICD) Registry on the entirely S-ICD system are promising, but the impact of the S-ICD system on patients' quality of life (QoL) is not known. We evaluated the QoL of patients with an S-ICD against an unrelated cohort with a transvenous (TV)-ICD system during 6 months of follow-up. Consecutively implanted patients with an S-ICD system were matched with patients with a TV-ICD system on a priori selected variables including baseline QoL. QoL was measured with the Short-Form Health Survey at baseline, 3, and 6 months after implant and compared using multivariable modeling with repeated measures. Patients with an S-ICD (n = 167) versus a TV-ICD system (n = 167) did not differ significantly on physical (p = 0.8157) and mental QoL scores (p = 0.9080) across baseline, 3, and 6 months after implantation in adjusted analyses. The evolution in physical (p = 0.0503) and mental scores (p = 0.3772) during follow-up was similar for both cohorts, as indicated by the nonsignificant interaction effect for ICD system by time. Both patients with an S-ICD system and a TV-ICD system experienced significant improvements in physical and mental QoL between time of implant and 3 months (both p's <0.0001) and between time of implant and 6 months (both p's <0.0001) but not between 3 and 6 months (both p's >0.05). In conclusion, these first results show that the QoL of patients with an S-ICD versus TV-ICD system is similar and that patients with either system experience improvements in QoL on the short term.