Doctors training to become general practitioners (GPs) enter new "communities of practice". For instance, they initially experience various types of isolation, need new skills and knowledge and find the organisation of general practice different to hospitals. "Communities of practice" concepts help explain some of their experiences. The social nature of learning is shown by their need for relationships that support them and the diverse ways in which they receive feedback. But there are limitations to communities of practice concepts. The registrars need to feel an important part of the practice; we argue that "peripheral participation" is an uncomfortable position for them. The importance of individual consultations with patients in registrars' learning experiences means that defining shared goals of the particular community of practice is also problematic. It may be useful to regard relationships with patients as part of the complex social relationship web within the community of practice rather than its object. (Contains 1 note and 1 table.)