We used an electronic medical records system retrospectively to evaluate how frequently, in a public hospital and its clinics, combined gonorrhea/chlamydia tests were accompanied by a syphilis test before and during a syphilis outbreak.Among 70,330 gonorrhea/chlamydia tests (1996-2000), the proportion with a syphilis test increased from 13% (preoutbreak) to 50% (intervention period) for men and from 6% to 13% for nonpregnant women. The increased syphilis testing coincided with a multifaceted public health intervention.