A 31-year-old nurseryman developed progressive respiratory failure secondary to paraquat poisoning after repeated and prolonged exposure. Ventilatory assistance proved inadequate to maintain satisfactory oxygenation, and extracorporeal membrane oxygenator support was instituted. A right lung transplantation was performed, but the transplant subsequently was damaged when lethal levels of paraquat entered the bloodstream from muscle reservoirs. Membrane oxygenation was reinstituted for 19 days during which time charcoal hemoperfusion reduced paraquat levels to the undetectable range. A left lung transplantation was then performed, after which pulmonary gas exchange no longer posed a problem. The patient subsequently developed a progressive, severe, toxic myopathy with generalized weakness and inability to maintain spontaneous ventilation. Death occurred from a cerebrovascular accident after a trachea-innominate artery fistula, 93 days after the initial lung transplantation and 71 days after the second one. The development of progressive toxic myopathy following severe Paraquat poisoning has not been previously recognized, presumably because most victims of fatal paraquat poisoning survive only a brief period.