Focusing on Nietzsche’s “middle period,” I argue that in those works friendship serves a vital function in Nietzsche’s account of self-creation, and that there a kind of self-knowledge figures importantly. It is knowledge not of a self per se, but of an ineliminable need for what Nietzsche will call self-overcoming, the imperative to understand oneself as importantly constituted by processes of change and development rather than as the logical or transcendental condition of such processes. Friends figure in such processes because they are best placed to propel us on the particular path down which our development leads by making life seem worthwhile, and so making the processes of self-creation matter too. Here, I discuss Nietzsche’s view of friendship and self-knowledge as it compares to that of Aristotle. And I attempt to show how Nietzsche’s positive account of friendship and self-knowledge makes sense against the background of his more general criticisms of modern morality.