Background: Electronic health (eHealth) interventions have proven effective, but implementation in clinical practice is difficult. More research focusing on the implementation process of eHealth interventions is necessary. Objective: The objective of this study was to describe the process evaluation of a perioperative eHealth intervention, aiming to enhance recovery after laparoscopic abdominal surgery. Methods: A process evaluation was carried out alongside a multicenter randomized controlled trial. Patients aged between 18 and 75 years who were scheduled for a laparoscopic cholecystectomy, hernia inguinal surgery, or laparoscopic adnexal surgery were included. The eHealth intervention comprised a website and mobile phone app with the possibility to develop a personalized convalescence plan, a section with information about the surgical procedure and the recovery period, the possibility to ask questions via an electronic consultation (eConsult), and an activity tracker. The process evaluation was carried out using the model of Linnan and Steckler, measuring components such as reach, dose delivered, dose received, fidelity, and participants' attitudes. Implementation scores were calculated based on the average of the four components. Quantitative data were collected by means of an electronic questionnaire, a logistic database, a weblog, and medical files. Qualitative data were collected by conducting interviews with a subsample of the study participants. Results: A total of 344 of the 863 eligible patients were included in the study, which accounted for a reach of 39.9%, and 173 participants were randomized to the intervention group. The implementation scores of the different functions of the intervention ranged between 60% and 65%. The website, mobile phone app, and activity tracker were rated 7.3 to 7.6 on a scale of 1 to 10. Almost all participants who were interviewed about the eConsult function rated it as being of additional value if combined with the usual care but not as a replacement for usual care. Conclusions: Although participants were overall satisfied with the intervention, the implementation scores of the different functions of the intervention were fair. More research is needed to evaluate the barriers and facilitators for implementation of this perioperative eHealth intervention in normal practice outside study setting.