The expansion of biomedical sciences has seen a recent boom in the number of graduate students and early career scientists. However, the lack of motivation and increasing departure of graduates from research careers were not well explained in current literature. Elements such as intrinsic motivation and external factors may play moderating or independent roles in altering these outcomes. Using semi-structured interviews, we sought to investigate the role of intrinsic motivation and external factors in shaping biomedical sciences graduate students’ and early career biomedical scientists’ research experiences, and the impact on their perceived research performance and expected career longevity. Using thematic analysis, our data from 10 graduate students or early biomedical scientists participants from uncover several aspects of intrinsic motivation such as its intensity, foundation and nature, and specific external factors such as the presence or absence of social support, the need for career progression driven by societal pressure, and the nature of the research environment that could all influence the students’ and trainees’ psychological state of mind. In turn, this could impact their perceived research performance ability, and desire to stay or leave the biomedical research field. Our study provided an in-depth perspective into the underlying reasons for leaving biomedical sciences or the lack of ‘feel-good’ in research besides competition, funding and publications. This could lead to further discussions on policy changes and interventions that could improve biomedical sciences graduate education and training in future.