Background: Women entering jails are at high risk for sexually transmitted diseases; however, screening for chlamydial and gonococcal infection is not routinely performed in most jails. New urine tests have made it easier to screen for these infections in nonclinical settings. Goal: The feasibility and acceptability of urine-based screening for women entering jails and the prevalence of and treatment rates for chlamydial and gonococcal infections were determined. Study Design: Women entering jails in Chicago, Illinois; Birmingham, Alabama; and Baltimore, Maryland, who signed consent forms were tested for chlamydial and gonococcal infection by means of the urine ligase chain reaction assay. Those testing positive were treated in jail; health department staff members attempted to contact those already released. Results: Most women who were approached agreed to be tested (range, 87-98%, depending on city), and most of these women provided a specimen (range, 92-100%). Among 5364 women aged 16 to 75 years who were tested, the prevalence of chlamydial and gonococcal infections was high, especially among those <25 years of age (range, 15.3-21.5% for chlamydial infection and 8.2-9.2% for gonorrhea, depending on city). The majority of women testing positive were treated in jail or outside of jail (61-85%). Conclusions: Screening women in jails for chlamydial and gonococcal infection with urine tests is feasible, is acceptable to most women, and leads to detection and treatment of many infections. Routine screening should reduce medical complications in this population and should prevent transmission in the community, given that many women are soon released.