OBJECTIVES: To determine the frequency of physician-documented sexual histories in female adolescents who presented to an emergency department (ED) with symptoms suggestive of a sexually transmitted infection (STI). Our secondary objectives were to determine if physician-documented sexual history is associated with increased STI testing and to compare the concordance of physician-elicited sexual histories with patient-documented sexual histories by using confidential questionnaires. METHODS: We conducted a secondary analysis of a prospective study of female adolescents who presented to a pediatric ED with chief complaints of lower abdominal pain and/or genitourinary complaints. Patient charts were abstracted for the presence or absence of documented sexual histories and demographics. A subset of patients completed a questionnaire pertaining to sexual health. RESULTS: The study population comprised 327 patients; 269 (82%) patients had a physician-documented sexual history, of which 204 (76%) reported being sexually active to the physician. Patient age (odds ratio [OR]: 2.6 [95% confidence interval (CI): 1.3-5.3]) and black race (OR: 2.0 [95% CI: 1.1-3.7]) were associated with physician-documented sexual history. The documentation of a sexual history was associated with increased STI testing (OR: 3.9 [95% CI: 2.0-7.6]). In the patients (n=109) who completed the questionnaire, physician-elicited sexual histories were highly concordant with patient-documented sexual histories on questionnaire (Spearman r=0.90; P<.001). CONCLUSION: These results indicate that ED physicians should obtain sexual histories from symptomatic patients, because it may increase STI testing and subsequent detection. In future studies factors should be evaluated that affect physicians' willingness to assess sexual history in the ED patient.