Twenty-one cases of a vegetative state (VS) caused by various kinds of brain damage were evaluated neurologically and electrophysiologically three months after brain injury. These cases were treated by deep brain stimulation (DBS) therapy, and followed up for over 10 years. The mesencephalic reticular formation was selected as a target in two cases, and the thalamic centre median-parafascicular (CM-pf) complex was selected as a target in the other 19 cases. Eight of the 21 patients emerged from the VS, and became able to obey verbal commands. However, they remained in a bedridden state except for one case. DBS therapy may be useful for allowing patients to emerge from a VS, if the candidates are selected according to appropriate neurophysiological criteria. A special neurorehabilitation system may be necessary for emergence from the bedridden state in the treatment of VS patients. Further, DBS therapy is expected to provide a useful method in minimally conscious state (MCS) patients to achieve consistent discernible behavioural evidence of consciousness, and emergence from the bedridden state.