This study applies the Theory of Planned Behaviour (TPB) to increase understanding about dishonest academic behaviour amongst undergraduate business students. A total of 579 respondents from three universities in South Africa completed an online survey about their beliefs regarding academic dishonesty, their intentions to engage in dishonest academic behaviour and their recent history of dishonest academic behaviour. A partial least squares (PLS) structural model shows that the TPB significantly explains dishonest academic behaviour. Validated TPB models that help to predict dishonest academic behaviour should be helpful in designing interventions to decrease academic dishonesty and thereby help to prevent later unethical business practices.