The Centers for Disease Control and Prevention recommends sexually transmitted disease (STD) screening among human immunodeficiency virus (HIV)-infected persons as a means of HIV prevention. HIV-infected persons in care may be an important target group in which to conduct regular STD screening to prevent enhanced transmission of HIV. We conducted STD screening for syphilis and two causes of urethritis, chlamydia, and gonorrhea, among 447 HIV-infected persons at two busy, urban clinics in San Francisco: a general HIV acquired immune deficiency syndrome (AIDS) care clinic and a methadone maintenance clinic. There were no new cases of syphilis identified and only two prevalent cases of chlamydia. While STD screening was feasible and acceptable in this population, the benefits of screening for asymptomatic gonococcal and chlamydial infection remain to be determined. Because these two pathogens only cause about 20% of urethritis, broader screening tests for urethritis, e.g., leukocyte esterase or urine microscopy, may be more useful. Finally, this study reaffirms the notion that local data should be used to evaluate national screening recommendations.