Background: The majority of women with tubal damage do not have a history of acute pelvic inflammatory disease. The prevalence of upper genital tract inflammation was evaluated in women deemed not to have pelvic inflammatory disease by common diagnostic criteria. Goal of this Study: To compare clinical signs and laboratory tests used to diagnose pelvic inflammatory disease with en-dometrial biopsy histopathology. Study Design: Endometrial biopsy and commonly used physical and laboratory tests were performed on 52 women with pelvic tenderness, 51 with vaginosis or cervicitis, and 22 control subjects who had no evidence of infection with Neisseria gonorrhoeae or Chlamydia trachomatis and who tested negative for bacterial vaginosis using vaginal swab Gram’s stain. Results: Thirty-six of 52 patients (69%) with pelvic tenderness, compared with 22 of 51 patients (43%) with vaginosis or cervicitis and two of 22 control subjects (9%), had plasma cell endometritis. The Centers for Disease Control and Prevention minimal diagnostic criteria for pelvic inflammatory disease had a sensitivity of 33% for plasma cell endometritis. Conclusions: The clinical diagnosis of pelvic inflammatory disease using published criteria correlates poorly with plasma cell endometritis.