Tetanus may be mild, moderate, severe, or inevitably fatal. Our clinical experience suggests it may be classified as severe (or, maybe, inevitably fatal) when a tetanic spasm stops respiration. Ten patients with severe tetanus were treated by the total paralysis regime (T.P.R.), consisting of tracheostomy, curarization, and intermittent positiveor positive/negative-pressure respiration. Two of the patients were saved by T.P.R. and therefore only limited effectiveness can be claimed for the regime. In inevitably fatal cases survival can be prolonged by T.P.R. so that further effects of tetanus toxin emerge. Of these, the most important appears to be direct damage to the myocardium.