Background: A volunteer program to test non-healthcare-seeking women for genital Chlamydia trachomatis infection was instituted at the US Army's largest basic training center and evaluated for its effectiveness in reducing sequelae. Goal: To compare hospitalization rates between women with positive test results for C trachomatis and those with negative results, and between women tested and those not tested for C trachomatis. Study Design: For this study, 28,074 women who entered the Army in 1996 and 1997 were followed for hospitalizations through December 1998. Of these women, 7053 were tested for C trachomatis, and 21,021 were not screened. Hospital admissions were calculated per person-year, and adjusted relative risks were determined. Results: The overall prevalence of C trachomatis in the screened group was 9.1%. The relative risk of hospitalization for pelvic inflammatory disease in the screened cohort was 0.94 (95% CI, 0.69-1.29), as compared with those not screened. The relative risk of hospitalization for any reason was 0.94 (95% CI, 0.90-0.99). Among women screened, no difference was found in pelvic inflammatory disease hospitalizations between women with positive test results who were being treated for C trachomatis and those with negative test results. Conclusions: The investigated C trachomatis intervention program for female Army recruits was associated with a lower overall hospitalization rate in screened volunteers, as compared with unscreened women. The pelvic inflammatory disease hospitalization rate in women with C trachomatis who were screened and treated was similar to that observed in uninfected women.