Supporting individuals’ progression into, and completion of post-compulsory education is a key strategic policy of the UK government. However, the number of learners withdrawing from Further Education (FE) prior to qualification completion has been highlighted as an area of concern within the UK. Consequently, we aimed to explore why learners withdraw from FE. We conducted semi-structured interviews with 85 learners who had withdrawn from a FE programme in Wales in the previous 24 months. Utilising thematic analysis through an abductive approach, we identified 318 individual meaning units that were categorised into three main themes for withdrawal: (a) personal; (b) course; and (c) institutional. Personal factors (e.g. social issues; physical health) were reported to be the most prevalent, with issues relating to mental health and well-being considered as the most influential cause for learner withdrawal (n= 57 participants highlighting this as a significant contributing reason). Linked to this, we highlighted the importance of learners being able to cope with the demands they experience and institutions satisfying learners’ basic psychological needs as ways of promoting mental well-being and improving retention. Collectively, our findings offer insights into learner retention in FE and support the need for greater emphasis to be placed on facilitating successful learner transition into FE, the importance of improving perceptions of institutional belonging, and the need to promote mental health and well-being in learners as well as the characteristics that might support their abilities to cope.