The diagnosis and management of patients requires professional know-how or medical craft knowledge. To explain how this knowledge is acquired, this research asked 'How do medical experts pass on their craft?' Other questions arose through successive data collections and progressive focusing on what medical experts did well in their work and teaching. The programme comprised: pilot interviews with three expert physicians; a case study in a hospital medical unit; and paired consultant/SHO interviews. Participant observation, interviews, and expert-novice comparisons explored clinical work, teaching, and learning in apprenticeship. Data analysis of participants' responses and ward round discussions allowed identified categories to cluster within three inter-related constructs instrumental to the acquisition of medical knowledge: gaining experience in the experiential process of clinical practice (1); and the products of experience which manifest as experts' clinical expertise (2) and teaching/learning expertise (3). These constructs can be located within a model of apprenticeship based on Spady's (1973) analysis of authority in effective teaching containing two frames of reference: the social, 'traditional-legal'; and the individual, 'expert-charismatic'. The medical apprenticeship is associated with similar perspectives: the 'traditional-experiential' represents the professional process of learning through patient care with its infrastructure of clinical methods in presentation, discourse, and commentary; and the 'expert-charismatic' represents clinical and teaching expertise coupled with vocational enthusiasm. Experienced experts synthesised two repertoires of knowledge and skills derived from the craft knowledge of medicine and pedagogy, respectively. Both crafts are required for effective clinical education. While apprenticeship accommodates a range of teaching/learning experiences, in postgraduate education experts pass on knowledge through the deliberate engagement of junior doctors in diagnosis and management. The skills involved in this process were largely unrecognised by most senior and junior doctors and were not perceived as 'clinical teaching' although learning was structured through service-based work.