Collusion in the healthcare setting occurs when a patient’s loved ones seek healthcare professionals’ cooperation in hiding or moderating the disclosure of a serious illness from the patient with capacity to make their own healthcare decisions. Collusion more commonly occurs in patients who are older, perceived as vulnerable and in need of protection from the harsh truth. When collusion occurs, the patient is excluded from the decision-making process, their autonomy is suspended, and advance care planning is not even an option. Collusion may be justifiable if the doctor exercises therapeutic privilege and withholds diagnostic and/or prognostic information from the patient because of concerns that the patient may be seriously harmed physically or psychologically, if informed. The highest court in Singapore in the recent case of Hii Chi Kok v Lucien London Ooi expanded the concept of therapeutic privilege. The court endorsed the view that therapeutic privilege should not be abused by doctors to prevent patients with mental capacity from deciding for themselves just because the doctors think their choice is not in their best interests. However, it seemed to leave the door open for the possibility of triggering the therapeutic privilege if the patient is impaired in their decision-making capabilities, although still possessing mental capacity, and refuses low-risk beneficial treatment because they misunderstand the rationale treatment for it, even with appropriate assistance. Are there limits to an individual refusing beneficial treatment? Is this compatible with respecting an individual’s right to make an unwise decision? Where should the line be drawn?