Although commentators sometimes mention a link between Kant and Nietzsche, this paper claims that the continuities in their moral thought have been insufficiently explored. I argue that Nietzsche may offer us a profound rethinking of Kant’s morality – one indebted to Kant’s ideal of critique. The paper first considers the wide apparent gulf between the thinkers. The second section seeks to explain this gulf in terms which relate to Kant’s overall project, while the final section deals with Nietzsche’s critique of Kant’s reliance on rules of various sorts. I conclude with two suggestions for contemporary Kantian ethics that we might take from Nietzsche’s engagement.