The classic observations of Sherrington (1898) demonstrated that in the cat transection of the brainstem between the superior colliculi and the vestibular nuclei consistently produced rigid involuntary extension of all four limbs. It is common clinical experience that a similar state occurs in man with compromise of the upper brain-stem, whether by compression by a supratentorial mass (McNealy and Plum, 1962) or by a primary destructive lesion within the brain-stem (Dinsdale, 1964). Decerebrate rigidity is almost always accompanied by coma, though preservation ofconsciousness has been acknowledged to occur rarely (Cairns, 1952). We wish to present three cases in which consciousness was preserved in the presence of decerebrate rigidity' The clinical signs were compatible with a lesion in the pons, sparing the midbrain and diencephalon. This anatomical diagnosis was confirmed in one post-mortem examination.