Lower genital tract specimens and endometrial biopsies from 147 women with pelvic inflammatory disease (PID) and surgical specimens (fallopian tubes, ovaries, or both) from 22 women with PID and 37 women without PID were cultured for cytomegalovirus (CMV) and herpes simplex virus (HSV), as well as for organisms commonly associated with PID. CMV was isolated from 39 cervical or endometrial samples from 30 (20.4%) of 147 women with PID and from ovaries or fallopian tubes from 5 (22.7%) of 22 women with PID, but CMV was not recovered from surgical specimens obtained from 37 women undergoing surgery for tubal ligation, ectopic pregnancy, or other gynecologic conditions (P = .005). HSV was isolated from cervical samples obtained from 5 (3.4%) of 147 women with PID but not from any endometrial or surgical specimens. These data suggest that CMV, but not HSV, may contribute to the pathogenesis of PID in some patients.