ABSTRACT The study of learning/research engagement in doctoral education has aroused increasing interest among education researchers, given its influence on PhD candidates’ experiences and outcomes. However, even if doctoral education has been recognised as emotionally intense, there is still a gap in the literature regarding the emotional dimension of engagement. This study aims to analyse the predictors of emotional engagement of PhD candidates enrolled in Portuguese higher education institutions. Data was collected through a survey and analysed using multiple linear regression and mediation analysis. Results showed that emotional engagement was fostered by autonomy-focused supervision, perceived relevance of the research project, personal development motivation, and inclusive academic context; and was hindered by professional motivation. Furthermore, our results showed that autonomy-focused supervision mediated the relationship between inclusive or competitive context and emotional engagement. This study reinforces that doctoral education has a strong emotional component and that promoting positive experiences should be an ethical imperative. As such, developing supervisors’ competencies and practices that nurture the autonomy of PhD candidates requires inclusive research contexts and working conditions that allow supervisors to dedicate the necessary time and effort to support their supervisees. It also draws attention to the need to choose research topics perceived as relevant by PhD candidates and manage motivations and expectancies.