To characterize the flora of early postpartum endometritis and the clinical features of women with specific organisms, endometrial cultures for facultative and anaerobic bacteria, genital mycoplasmas, and Chlamydia trachomatis were taken with a triple-lumen sampling device. More than one organism was recovered from 80% of the women. Over 60% of the women had Gardnerella vaginalis and/or anaerobes associated with bacterial vaginosis isolated from the endometrium; these women were more likely to have severe illness and to develop a wound infection than were other women. Genital mycoplasmas were isolated frequently, but specific antibiotic therapy was not required for clinical cure in the 10% of patients who had Ureaplasma urealyticum only. Chlamydia trachomatis was infrequently isolated, but C trachomatis commonly remained after therapy.