An analysis of data from 30 subjects diagnosed as being in vegetative state (VS) on admission to a specialized Brain Injury Unit was carried out. Rancho Level ratings given by the referring physician were compared with those of the units occupational therapists (OT). Scores were obtained from the Sensory Modality Assessment Technique (SMART) and the Western Neuro Sensory Stimulation Profile (WNSSP) on admission and at 2 monthly intervals and converted to Rancho Level ratings to allow comparison. The comparison of the assessments within one week of admission showed agreement between Rancho Level scores derived from the WNSSP and those from the referring physicians. The Rancho scores derived from the SMART were significantly different from the physicians' and the WNSSP (P < 0.01), with the SMART rating the patient at a higher level of cognitive functioning. Although all 30 subjects were diagnosed as VS on admission, the SMART assessed six subjects not to be in VS within 2 to 4 months from admission and this was established at least 6 weeks earlier than the comparable conclusion from the WNSSP in four subjects. This initial validation study shows that the SMART is a useful tool in discriminating awareness and more sensitive at detecting the higher cognitive functions than both the WNSPP and referring physician, thus indicating the need to conduct a specifically designed prospective study to validate and further evaluate the SMART.