The presence of antibodies to pili of Neisseria gonorrhoeae and Chlamydia trachomatis serovar L2 were assessed in women consecutively hospitalized in Zimbabwe with pelvic inflammatory disease (PID; n = 66), infertility (n = 227), and ectopic pregnancy (n = 60). Women delivering live full-term infants served as controls. Of the infertile women, 60% had secondary infertility; 59% had macroscopic evidence of a tubal abnormality. Women with PID, infertility and tubal disease, and ectopic pregnancy and tubal disease had significantly higher prevalences of antibodies against C. trachomatis and N. gonorrhoeae than did controls or women with infertility or ectopic pregnancy but no macroscopic tubal abnormalities (P <.001 for all comparisons). The prevalence of antibody to chlamydia increased with age (P =.01), unlike the gonococcal antibody. Antibodies to C. trachomatis were associated with a history of PID and with antibody to N. gonorrhoeae. Gonococcal antibody correlated with a history of PID, being single, a positive Treponema pallidum hemagglutination assay, and chlamydial antibody. None of the controls had human immunodeficiency virus, unlike 3.9%–7.6% of the other women. Tubal abnormalities were implicated in more than half of the cases of infertility. © 1990, by The University of Chicago.