OBJECTIVES: To evaluate clinician adherence to guidelines for documentation of sexual history and screening for sexually transmitted infection (STI)/HIV infection during routine adolescent well visits. Secondary objectives were to determine patient and clinician factors associated with sexual history documentation and STI/HIV testing. STUDY DESIGN: Retrospective, cross-sectional study of 1000 randomly selected 13- to 19-year-old routine well visits at all 29 pediatric primary care practices affiliated with a children's hospital. We evaluated frequency of documentation of sexual history and testing for gonorrhea (GC)/chlamydia (CT) and HIV testing. Multivariable logistic regression was performed to identify factors associated with documentation and testing. RESULTS: Of the 1000 patient visits reviewed, 212 (21.2%; 95% CI, 18.7-23.7) had a documented sexual history, of which 45 adolescents' (21.2%; 95% CI, 15.7-26.8) encounters were documented as being sexually active. Overall, 26 (2.6%; 95% CI, 1.6-3.6) patients were tested for GC/CT and 16 (1.6%; 95% CI, 0.8-2.4) were tested for HIV infection. In multivariable analyses, factors associated with sexual history documentation included older patient age, non-Hispanic black race/ethnicity, nonprivate insurance status, and care by female clinician. Factors associated with GC/CT testing included male gender, non-Hispanic black race/ethnicity, and nonprivate insurance. HIV testing was more likely to be performed on older adolescents, those of non-Hispanic black race/ethnicity, and those with nonprivate insurance. CONCLUSIONS: Pediatric primary care clinicians infrequently document sexual histories and perform STI and HIV testing on adolescent patients. Future studies should investigate provider beliefs, clinical decision-making principles, and perceived barriers to improve the sexual health care of adolescents and evaluate interventions to increase rates of adolescent sexual health screening.