In this article I will show that 'best interests' is a concept that fits nicely with many of the features of pragmatism--Holm and Edgar's rejection of the principle in favour of pragmatism it will be suggested is misplaced. 'Best interests' as a principle may be considered an embodiment of the ideals of pragmatic adjudication. The paper starts by briefly introducing the concept of 'best interests' and theories of judicial and legal 'pragmatism'. This article will examine the role of the rational decision-maker in medical law and argue that this role is limited. The paper concludes by suggesting how we view the relationship between 'best interests' and 'pragmatism'.