Abstract Background The safety and efficacy of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy are well-established. However, there is a paucity of patient-reported outcome data, despite the increasing emphasis on incorporating patients' perspectives into quality care assessments. Current guidelines also recommend evaluating psychological status and addressing distress in defibrillator patients. Purpose This study aims to assess perioperative and postoperative pain during S-ICD implantation, along with patient acceptance during follow-up. We also explore associations between these outcomes, clinical characteristics, and implantation variables. Methods A total of 149 consecutive patients (87% male, mean age 53±13 years, body mass index 27±4 Kg/m², ejection fraction 39±14%) who underwent S-ICD implantation across 11 centers were analyzed. Short-term endpoints included pain during and 6 hours after the procedure. Pain intensity was rated on a 10-point visual analogue scale. Long-term endpoint was S-ICD patient acceptance measured (on a 0-to-100 point scale) by the Florida Patients Acceptance Survey (FPAS) score and its components: Return to Function (RTF), Device-Related Distress (DRD), Positive Appraisal (PA), and Body Image Concerns (BIC). The survey was administered 12 months post-implantation. Results The S-ICD generator was positioned in an intermuscular pocket in 140 (94%) patients. Serratus anterior plane block (SAPB) was performed in 103 (69%) patients. 72 (48%) patients underwent the defibrillation testing. Implantation success was reported in all patients without operative complications. Overall, pain intensity during implantation was 2 [25th-75th percentile: 1-4], and 1 [1-2] for static pain and 2 [1-3] for dynamic pain, 6 hours post-procedure. SAPB was associated with significantly lower pain intensity during implantation (2 [1-3] vs. 4 [2-5], p<0.001) and non-significantly lower values of dynamic pain intensity 6 hours post-procedure (1 [1-2] versus 2 [1-3], p=0.076). The other tested variables, i.e. age, sex, body habitus, ejection fraction, omission of defibrillation testing, were not associated with different pain levels. S-ICD acceptance scores were favorable overall (total FPAS 77 [63-87], RTF 69 [56-88], DRD 25 [10-45], PA 88 [75-100], BIC 13 [0-38]). Patients who underwent SAPB exhibited better RTF (75 [56-88] versus 63 [50-69], p=0.002) and PA (88 [75-100] versus 75 [69-94], p=0.004). Conclusions S-ICD implantation resulted in minimal discomfort, especially with novel anesthetic techniques. Overall, patients reported good acceptance of the S-ICD. Improved acceptance was observed in patients who underwent SAPB, highlighting the significance of enhanced patient implantation experience for long-term outcomes.