This study examined partners of cancer patients intention to use a web-based psychological intervention, their preferences regarding its preconditions, functionalities and topics, and factors related to their intention. One hundred and sixty-eight partners completed a questionnaire about these aspects. Forty-eight percent of the partners would (maybe) make use of a web-based intervention. Partners who intended to participate were significantly younger, used the Internet more often, and perceived more caregiver strain. Most partners preferred an intervention that takes less than 1 hour/week, lasts five weeks or more, and contains information and peer support. Half of the partners would like to receive online guidance.