Action-oriented entrepreneurship training can boost entrepreneurship, but positive short-term effects often decay over time. Based on training transfer theory, we argue that error mastery orientation is a personal characteristic that affects the maintenance of training outcomes over time in the transfer context of entrepreneurship. We implemented an action-oriented entrepreneurship training at a university in Uganda and collected data from training participants before (N_T0 = 175) and after the training programme (N_T1 = 164) as well as at a 1-year follow-up measurement (N_T2 = 52). Growth curve models showed that the participants experienced an increase in entrepreneurial action and new venture creation over time. Furthermore, error mastery orientation influenced the maintenance of entrepreneurial action and new venture creation over time. The study contributes to theories of entrepreneurship training and training transfer by demonstrating that error mastery orientation is a boundary condition of the long-term effectiveness of active learning interventions, such as action-oriented entrepreneurship training.