My article focuses on the Derridean aporias of unconditional and conditional hospitality. I argue that Kleist’s play Amphitryon performs a two-fold deconstruction of the elementary conventions of hospitality. First, hospitality is practiced only after the guest is (falsely) recognized as the head of the household, which on the one hand confronts us with the impossibility of hosting the host, but on the other hand points to a possible condition of unconditional hospitality, which is the anonymity – and hence interchangeability – of the guest and the host. Second, and not independently from the first, Kleist’s play also illuminates not-knowing or the unknown as a key factor of hospitality, which makes hospitality an open secret in the sense that its conditions are never fully revealed but have never been fully concealed either.