In the Province of Quebec, an adolescent aged 14 years or older may, subject to a few exceptions, consent alone to medical treatment required for his or her condition. However, neuroscience research on the adolescent’s brain indicates that: 1) the acquisition of “brain maturity” is a continuing process, which can last until the mid-twenties and 2) certain decisional capacities such as assessment of short and long-term risks and benefits differ from those of adults, particularly in emotionally charged situations. I argue that, from the perspective of a child’s best interest, the neurophysiological capacity of the adolescent should be taken into consideration in the health care context. Thus, I question the adequacy of the presumption of ability to make autonomous judgments from the age of 14, and point out the paradox of allowing judicial review of such judgments in cases of refusal of treatment. I also question the relevance of age considerations in the context of the doctor-patient relationship, where assessment of decisional ability is of the essence in obtaining an informed consent. Finally, I question the exclusion of parents from the decision-making process in light of both their continuing responsibility to protect their child’s best interests and the benefits that parental guidance may provide to the adolescent. Consequently, I argue that a reconsideration of the case for giving decisional authority to the adolescent aged 14 or older is desirable and that a uniform standard, with a few possible exceptions, applicable throughout childhood would better reflect recent neuroscience findings.