With the high prevalence of unprotected sexual activity among adolescents, health-care providers are frequently called upon to evaluate patients with abnormal vaginal discharges. Usually, thorough pelvic and laboratory examinations will identify offending organisms which can be promptly eradicated with the judicious use of antibiotics. Occasionally, however, an abnormal discharge may persist despite these interventions. Health-care providers need to be aware of the fact that anal intercourse may be a common practice among sexually active teenagers. Penile-vaginal contact after anal intercourse may cause vaginal discharge due to contamination. Health-care providers should make it a routine part of their history-taking of adolescent patients to inquire about anal intercourse. Not only might it reveal useful clinical information, but it may indicate the need for additional health education and counseling.