Using the example of an unconsented mouth swab I criticise the view that an action of this kind taken in itself is wrongful in respect of its being a violation of autonomy. This is so much inasmuch as autonomy merits respect only with regard to ‘critical life choices’. I consider the view that such an action is nevertheless harmful or risks serious harm. I also respond to two possible suggestions: that the action is of a kind that violates autonomy; and, that the class of such actions violates autonomy. I suggest that the action is wrongful in as much as it is a bodily trespass. I consider, and criticise, two ways of understanding how morally I stand to my own body: as owner and as sovereign. In respect of the latter I consider Arthur Ripstein’s recent defence of a sovereignty principle. Finally I criticise an attempt by Joel Feinberg to explain bodily trespass in terms of personal autonomy.