Objective: Sudden cardiac arrest caused by cardiac arrhythmias is 1 of the leading causes of death worldwide. Implantable cardioverter defibrillators (ICDs) are considered as standard care for patients with increased risk of arrhythmias. However, 1 in 4 ICD patients experiences psychological distress post-ICD implantation. The WEB-based distress management program for ICD patients (WEBCARE) was developed to mitigate anxiety and depression and enhance health-related quality of life in ICD patients. This study investigates the 6- and 12-months outcomes. Method: A total of 289 consecutive ICD patients from 6 referral hospitals in the Netherlands were randomized to either the WEBCARE (n = 146) or usual care (n = 143) group. Patients in the WEBCARE group received an online, 12-weeks fixed, 6 lesson behavioral treatment based on problem solving therapy. Patients in the usual care group receive care as usual. Results: Current findings show no significant difference on anxiety, depression or quality of life between the WEBCARE and Usual Care group at 6- and 12-months postimplantation. Conclusions: In this clinical trial of a Web-based behavioral intervention for ICD patients, the Web-based treatment was not superior to usual care on the long-term regarding patient reported outcomes. Future studies are warranted to examine the applicability of blended-care models and focus on further personalizing the program in order to increase adherence and improve outcomes.