This sample of listerial infection amongst perinates is biased by small numbers and ascertainment. Nevertheless, it includes a broad spectrum of disease, with examples of established intrauterine septicemia, amniotic infection syndrome, intrapartum infection, and postnatal infection. The study shows that amniotic infection may eventuate in gestational loss, with or without invasive bacteremia and septicemia. Noteworthy are the association of perinatal listeriosis with abnormality of the birth canal, the occurrence of mixed primary infection and superinfection, and the frequency of findings suggesting underlying metabolic or humoral abnormalities. Excepting well-established septicemia with characteristic histopathology and distribution of lesions, the morphologic findings are not distinctive and are liable to be dominated by secondary complications, among which are changes reminiscent of disseminated intravascular coagulopathy, endotoxemia, and circulatory compromise.