Student engagement models predominantly encompass three primary aspects: emotional, cognitive, and behavioral engagement. Certain authors propose a fourth aspect of engagememt, proactive engagement, representing a deliberate and constructive contribution to personal learning activities, which in turn enriches the learning process. There are many previous studies on determinants of proactive engagement among students, however, there is a notable lack of research of pre-service teachers’ engagement. This research gap forms the basis for this study, which intends to identify the individual and contextual determinants of proactive engagement of pre-service teachers during their studies. To answer research questions, 14 semi-structured interviews were conducted with pre-service primary school teachers and subject teachers. The interviews were transcribed and a thematic analysis was performed. The results suggest that from the pre-service teachers’ perspective, contextual determinants that have the most substantial impact on students' proactive engagement were the teachers' characteristics and their relationship with the students . Other influential factors include the physical environment, the course's conception, fellow students, family, peers from different study programs, and professionals from related fields. On the individual level, the students report that current state — including their mood and their physical and mental health — can significantly influence proactive engagement. Additional individual determinants reported by students include motivation, interest in the learning content, personality traits, and prior knowledge. These findings are based on the personal experiences and opinions of the pre-service teachers. The results can thus guide not only them but also current teachers and university professors in their future interactions with students, with the goal of encouraging proactive engagement.