OBJECTIVE To investigate the accurate and objective methods of evaluating coma after cardiopulmonary resuscitation. METHODS Cases that were still in coma 24 hours after cardiopulmonary resuscitation were continuously observed and evaluated between April 2002 and November 2004. The methods of evaluation included various clinical examinations, for instance conscious state, Glasgow coma score (GCS), brain stem inflection, spinal reflexes and so on. Other methods of evaluation included laboratory examinations, such as electroencephalography (EEG), brain auditory evoked potential (BAEP), short latent somatosensory evoked potential (SLSEP) and transcranial doppler (TCD). RESULTS 24 of a series of 35 cases (68.6%) were in deep coma. The GCS is score 3. EEG evaluated was not less than grade IV in all except 4; BAEP evaluated was grade III in all except 3; SLSEP evaluated was grade III in all except 1. 24 cases died within 1 month and 11 of them (45.8%) were evaluated as having brain death and Glasgow outcome score (GOS) was grade I. 11 of the 35 cases survived and their state of consciousness changed from deep coma to coma vigil, EEG evaluated was grade I in 5 cases. BAEP and SLSEP were grade I in the 3 cases evaluated and GOS is grade II. 2 cases (18.2%) regain consciousness at the time of 35 and 90 days after cardiopulmonary resuscitation and their GOS was grade IV and grade III respectively. CONCLUSIONS Combined and continuous observation of clinical manifestations and laboratory parameters can accurately and objectively evaluate coma after cardiopulmonary resuscitation.