Bilateral paramedian thalamic infarcts are characterized by disturbance of consciousness, followed by persisting dementia, decreased spontaneity, apathy, amnesia and paralysis of eye movement. We report a 15-year-old boy with this syndrome, who exhibited transient coma at the onset. In addition to the typical symptoms, he complained of sensory disturbance in the lower extremities and face and the loss of taste sense. MRI showed symmetric paramedian thalamic infarction. There was no lesion in the midbrain. The etiology of infarct in this boy remained unknown despite extensive laboratory and neuroradiological examination. His sensory disturbance in the extremities and face may be due to extensive involvement of the inferolateral area of the thalamus by infarction of the paramedian thalamic artery. This patient illustrates that bilateral paramedian thalamic infarction can occur in a previously healthy child.