This study examines the relationship between the individual motivational characteristics of young scientists (i.e. PhD students and post-docs) and their entrepreneurial intention, exploring also the mediating role of their third mission orientation. For this purpose, the authors considered the knowledge spillover theory of entrepreneurship at the level of the individual and the Theory of Planned Behaviour. Having university scientists as the unit of analysis, they used structural equation modelling to survey a sample of 337 young scientists working in a major Italian university. The authors were able to empirically identify the importance of third mission orientation as a mediating variable between scientists' motivational characteristics and their entrepreneurial intention. The entrepreneurial orientation is reinforced if scientists are also engaged in third mission activities. The findings offer valuable insights for policy makers and higher education managers to develop strategies that could enhance knowledge transfer activities and produce additional benefits for universities and societies.