Medical decisions for children are usually justified by the claim that they are in a child's best interests. More recently, following criticisms of the best interests standard, some advocate that the family's interests should influence medical decisions for children, although what is meant by family interests is often not made clear. I argue that at least two senses of family interests may be discerned. There is a ‘weak’ sense (as the amalgamated interests of family members) of family interests and a ‘strong’ sense (that the family itself has interests over and above the interests of individuals). I contend that there are problems with both approaches in making medical decisions for children but that the weak sense is more plausible. Despite this, I argue that claims for family interests are not helpful in making medical decisions for children.