Ethical oaths for bankers, economists and managers are increasingly seen as successful instruments to ensure more responsible behaviour. In this article, we reflect on the nature of ethical oaths. Based on John Austin's speech act theory and the work of Emmanuel Levinas, we introduce a performative concept of ethical oaths that is characterised by (1) the existential self-performative of the one I want to be, which is (2) demanded by the public context. Because ethical oaths are (3) structurally threatened by the possibility of infelicity or failure, we stress (4) the behavioural aspect of ethical oaths in economics and business. We conclude that a performative concept of ethical oaths can contribute to more ethical behaviour in economics and business, because the performative involves action and behaviour. At the same time, it becomes clear that a radical new perspective on the nature, function and limitation of oaths is needed.