One of the key attributes that health professional students and new graduates develop during professional socialisation is clinical reasoning ability. Clinical reasoning is a complex skill that is essential for professional practice. There is limited research specifically addressing how physiotherapists learn to reason in the workplace. The research reported in this paper addressed this gap by investigating how experienced physiotherapists learned to reason in daily practice. This learning journey was examined in the context of professional socialisation. A hermeneutic phenomenological research study was conducted using multiple methods of data collection including observation, written reflective exercises and repeated, semi-structured interviews. Data were analysed using phenomenological and hermeneutic strategies involving in-depth, iterative reading and interpretation to identify themes in the data. Twelve physiotherapists with clinical and supervisory experience were recruited from the areas of cardiopulmonary, musculoskeletal and neurological physiotherapy to participate in this study. Participants' learning journeys were diverse, although certain episodes of learning were common or similar. Role models, mentors and colleagues were found to be influential in the development of reasoning. An important implication for the professional socialisation of physiotherapists and other health professionals and for those involved in practice development is the need to recognise and enhance the role of practice communities in the explicit learning of clinical reasoning skills.