Background: Patients with incurable cancer have to deal with a wide range of symptoms due to their disease and treatment, influencing their quality of life. Nowadays, patients are expected to adopt an active role in managing their own health and healthcare. Oncokompas is an eHealth self-management application developed to support patients in finding optimal palliative care, tailored to their quality of life and personal preferences. A randomized controlled trial will be carried out to determine the efficacy and cost-utility of Oncokompas compared to care as usual. Methods: 136 adult patients with incurable lung, breast, colorectal and head and neck cancer, lymphoma and glioma, will be included. Eligible patients have no curative treatment options and a prognosis of at least three months. Patients will be randomly assigned to the intervention group or the control group. The intervention group directly has access to Oncokompas alongside care as usual, while the waiting list control group receives care as usual and will have access to Oncokompas after three months. The primary outcome measure is patient activation, which can be described as a patient's knowledge, skills and confidence to manage his or her own health and healthcare. Secondary outcome measures comprise self-efficacy, health-related quality of life, and costs. Measures will be assessed at baseline, two weeks after randomization, and three months after the baseline measurement. Discussion: This study will result in knowledge on the efficacy and cost-utility of Oncokompas among patients with incurable cancer. Also, more knowledge will be generated into the need for and costs of palliative care from a societal and healthcare perspective. Trial registration: Netherlands Trial Register identifier: NTR 7494. Registered on 24 September 2018.