Respiratory paralysis is the most frequent cause of death in acute poliomyelitis. We have treated three of these cases in the Drinker respirator, with one recovery. So far as we know, this is the first reported recovery in a case in which the paralysis was severe enough to cause death without artificial respiration. The machine used is a modification of the apparatus described last spring by Drinker and McKhann,1and by Drinker and Shaw.2The three case histories follow. REPORT OF CASES Case 1. —B. H., a Harvard college student, aged 21, was admitted to the medical service of the Peter Bent Brigham Hospital, Sept. 13, 1929, as an emergency patient. Five days before he had awakened feverish with a headache and a slightly stiff neck. Two days later he began to notice weakness of his left arm and leg. A lumbar puncture showed increased pressure and a