The principle of patient self-determination has assumed central importance in British medical law in recent years. This article considers whether this increasingly strong commitment to patient autonomy has any resonance for abortion law. In particular, this article explores the possibility that the priority currently accorded to autonomous decision making may be in tension with the Abortion Act's requirement that a woman's reasons for seeking to terminate her pregnancy be judged acceptable by two medical practitioners. Moreover, interest in the moral legitimacy of a woman's reasons for wanting to terminate her pregnancy seems to be intensifying. Concerns arising from the increasing availability of precise prenatal tests have led to suggestions that access to abortion should be further restricted in order to prevent the cavalier use of abortion for reasons that might seem trivial or misguided. Using abortion following prenatal diagnosis as an example, this article considers whether it is anomalous for the common law's vigorous protection of an individual's freedom to make irrational or morally objectionable choices about his or her medical treatment to coexist with demands for further restriction of the acceptable grounds for abortion.