The purpose of the present study was to examine an extended theory of planned behaviour (TPB) model within the domain of sustainable entrepreneurship and identified the most important factors impacting on sustainable entrepreneurial intentions in sustainable entrepreneurship. In particular, the study aimed to extend the TPB model to include sustainability orientation and prior sustainability knowledge. Data were collected from 211 Iranian agriculture students. The results of structural equation modelling showed that sustainable entrepreneurial intentions were determined by attitudes toward sustainable entrepreneurship and perceived behavioural control (PBC) but not subjective norms. The analysis also revealed that sustainability orientation and prior sustainability knowledge influenced sustainable entrepreneurial intentions indirectly through their effects on attitudes toward sustainable entrepreneurship and PBC. As a practical implication, educators who want to stimulate the creation of new sustainable businesses could consider the pivotal role not only of attitudes toward sustainable entrepreneurship and PBC but also of sustainability orientation and prior sustainability knowledge. پرونده مقاله