The medical profession has an almost exclusive right to prescribe medicines, but this right is being challenged by the State, patients and other health care professionals. It is argued that, in British general practice, prescribing is a battleground on which the cause of clinical autonomy is defended. It represents a particular context for assessing the theories of proletarianisation and deprofessionalisation. The historical conflicts between the State and the medical profession, and the threat posed by ‘patient demand’, are both reflected in the regulations governing prescribing and the medicolegal status of medicines. Clinical freedom is under threat from the State and peer group pressure in the form of clinical governance, while at the same time doctors’ jurisdiction over medicines is being reduced by the deregulation of prescription-only medicines. These changes, however, do not yet support the thesis of proletarianisation as the medical profession continues to dominate the clinical agenda and the responsibilities of other health care workers. Neither does the concept of patient demand support the thesis of deprofessionalisation, as it is unsupported by the research evidence. Doctors cite patients’ inappropriate demands as problematic, but do not give patients the information about their medicines that they both want and need. Patients’ resistance tends to take the form of ‘non compliance’. In fighting two adversaries, patients’ expectations (‘clinical need’) are cited in support of professional claims, while in other contexts ‘patient demand’ is seen as a threat to clinical autonomy.