Prostate cancer has increased in incidence worldwide and is the leading cause of cancer death in 24 countries. The most common treatment is radical prostatectomy. However, surgery is associated with postoperative complications such as urinary incontinence and sexual dysfunction, causing decreased quality of life. If survivors are encouraged to be more active in self-care management, the symptom burden may decrease and quality of life may improve. An electronic health (eHealth) intervention based on motivational behavioral theory has been developed for this purpose.This study aimed to compare the effectiveness of standard care in combination with a tailored eHealth and mobile health self-management support system, electronic Patient Activation in Treatment at Home (ePATH), with standard care of adverse effects of prostate cancer treatment (urinary incontinence and sexual functioning) in men undergoing radical prostatectomy. The secondary aim was to test the effect on patient activaftion, motivation, overall well-being, and health literacy over time in and between groups.A pragmatic multicenter, block-randomized controlled trial with 2 study arms, standard care (control) and eHealth-assisted standard care (intervention), for patients undergoing radical prostatectomy. For 80% power, a sample of 242 men will need to be recruited.Recruitment started in January 2018 and is expected to be completed by August 2019. Data collection will be completed in August 2020. The first cross-sectional results from this trial are anticipated to be published in January 2020.With the increasing number of prostate cancer survivors, attention should be paid to rehabilitation, psychosocial care, and support for endurance of self-care to reduce suffering from adverse treatment effects, poor quality of life, and depression because of postoperative complications. This project may increase knowledge of how patients can be supported to feel involved in their care and returning to as normal a life as possible. The anticipated effects of ePATH could improve health outcomes for individuals and facilitate follow-up for health care professionals.International Standard Randomised Controlled Trial Number: 18055968; http://www.isrctn.com/ISRCTN18055968 (Archived by WebCite at http://www.isrctn.com/ISRCTN18055968).DERR1-10.2196/11625.