The clinical course of a young woman following two separate suicide attempts using the herbicide paraquat is reported. The patient survived an intramuscular injection of paraquat almost asymptomatically, but later exhibited a typical fatal course with fulminant proliferative pulmonary fibrosis after an intravenous injection. Fibrosis and death occurred despite a therapeutic regimen based upon a known action of paraquat, the generation of superoxide (O(2)[unk]), using superoxide dismutase, α-tocopherol, and ascorbic acid in conjunction with forced diuresis and prednisone. While treatment failed explanations for the failure of therapy in this case and current therapeutic alternatives are discussed so that they may be considered when future cases are encountered.