Interest in the persistent vegetative state has focused on the accuracy of diagnosis and prognosis. Retrospective studies in both adult and paediatric groups have raised questions about the most appropriate clinical methods to diagnose patients in the vegetative state and about the length of time before recovery from such a state can be regarded as hopeless. Although no absolute answers have been forthcoming, the debate engendered by the work has been informative and the need for further prospective studies is apparent. Following the publication of guidelines on the management of patients in the vegetative state, the views of physicians in the USA and Europe have been sought in relation to ethical problems and, although they highlight some areas of inconsistency, they show the potential for consensus. Clinically, the field of brain stem death is reasonably defined and consistently managed but the search for methods of technical confirmation of diagnosis continues. It is suggested that the use of magnetic resonance imaging and angiography might provide additional confirmatory evidence.