Clostridium sordellii is a common soil and enteric bacterium that is infrequently recovered from the vagina. We describe three women in which C. sordellii caused puerperal infection and a distinctive and lethal toxic shock-like syndrome. Patients were less than 1 week post partum and each had a single, limited focus of infection including infection associated with a retained vaginal sponge, a cesarean section operative site, and endometritis. Each patient had a distinctive course characterized by sudden onset of clinical shock marked by severe and unrelenting hypotension associated with marked, generalized tissue edema and "third spacing" with increased hematocrit, presence of marked leukemoid reaction with total neutrophil counts of 84,000/mm3, 66,000/mm3, and 93,600/mm3, absence of rash or fever, limited or no myonecrosis, and a rapid and uniformly lethal course. Hypoalbuminemia was also noted. Similar findings were noted in prior isolated reports of C. sordellii-mediated postpartum or surgical infection. Treatment of animals with C. sordellii or closely related C. difficile toxins produces similar findings. We suggest that localized infection with toxin-producing strains of C. sordellii can produce a rapidly lethal toxic shock-like syndrome. Further study and earlier recognition of this syndrome may be life-saving in other patients.