The acquired immunodeficiency syndrome epidemic has drawn attention to screening for sexually transmitted diseases by primary care physicians. A telephone survey of primary care physicians in an area with a high incidence of STDs (Washington, DC) to ascertain the determinants and the extent of screening and counseling for STDs was completed in 1987. Ninety-nine physicians (33 internists, 38 obstetrician/gynecologists, and 28 family/general practitioners), representing 61% of those eligible, completed the interview. One third (39.4%) were screening for gonorrhea, more than one half (57.5%) for syphilis, and almost all (94%) had tested at least one individual for human immunodeficiency virus infection. Analysis suggested that concomitant screening for hepatitis B was significantly and positively associated with screening for gonorrhea and syphilis. Less than half (45.9%) of the physicians asked new patients about their sexual practices. Physicians should take histories of sexual practices and do more preventive counseling.