In anaesthetized, mechanically ventilated rats with brain death induced by epidural balloon inflation, we assessed the levels of cerebral myo-inositol in three brain areas 4 h after brain death had been confirmed. The levels were measured using HPLC, along with the water content. Myo-inositol levels were significantly increased in the cerebellum (P<0.05) and decreased in the brainstem (P<0.001), compared to findings in controls. Such changes can serve as hallmarks of brain death.