Vaccination programs have significantly reduced the incidence of tetanus in the United States. The disease develops almost exclusively in those who have been inadequately immunized. This report describes severe, generalized tetanus in a 29-year-old man who had received a primary series as a child and two booster injections. Serum obtained before administration of tetanus immune globulin showed antibody titers to tetanus greater than 100 times the level considered protective. Aggressive supportive care can usually prevent serious consequences. Since most physicians have never seen a case of tetanus, however, the diagnosis can be difficult. Many disorders that exhibit signs and symptoms similar to tetanus must be carefully considered during the evaluation of these patients. Tetanus is a preventable disease. Prevention, however, requires both appropriate immunizations and prompt wound care. While controversy exists regarding the most effective policy to adequately immunize all individuals, this case shows that vaccination alone does not preclude the possibility of tetanus.