Pathologic changes in 12 fatal cases of toxic shock syndrome occurred in the vagina, cervix, lung, liver, and kidney. Desquamation and ulceration of the cervical and vaginal mucosa were seen in all six cases where adequate specimens were submitted. Hyaline membrane formation characteristic of "shock lung" was found in all lung tissues. Periportal inflammation was found in all liver specimens and acute tubular necrosis was seen in eight of the 12 kidney specimens. Although not specific for toxic shock syndrome, the findings are consistent with the hypothesis that the illness is caused by a staphylococcal toxin.