Transfundal endometrial cultures obtained from afebrile women who delivered vaginally were uniformly free of bacteria and contained Ureaplasma urealyticum in only 2 of 14 women. A protected triple-lumen transcervical method to obtain an endometrial culture recovered organisms from 6 (43%) of the 14 women. Compared with cultures from afebrile women, organisms were recovered from 51 (93%) of 55 febrile postpartum women by using the triple-lumen transcervical culture method (P less than .001). Among febrile women there was a correlation between the recovery of group B Streptococcus, enterococcus, Gardnerella vaginalis, Staphylococcus aureus, and anaerobic bacteria from the cervix and their recovery from the endometrium. Protected transcervical methods used to obtain postpartum endometrial cultures reduce cervical contamination, but semiquantitation of the culture is useful to further increase culture specificity.