Background. Pediatric urinary tract infections (UTIs) are markers for genitourinary reflux or obstruction. Adult UTIs are treated by telephone triage without microbiologic study. The contrast between pediatric and adult UTIs prompted our retrospective review of adolescent UTIs. Methods. Ninety six adolescent girls without chronic illness, urogenital abnormalities, pregnancy, enuresis or constipation had urine Cultures with 100,000 colonies/min(3). Results. The 32 patients who were initially sexually active continued sexual activity (75%), became pregnant (25%), and had Subsequent sexually transmitted diseases STDs) (13%). There were no pregnancies, STDs, or subsequent UTIs in 9 patients who were not initially sexually active. The 55 patients with no documentation of sexual activity were comparable to those who were initially sexually active 66% had evidence of sexual activity; 20% had subsequent pregnancy,; 14% had subsequent STDs; and 42% had UTI recurrence. Conclusion. Adolescents with UTIs have a significant frequency of sexual activity. Information about responsible sexual activity and access to care is important to adolescents, particularly those with UTIs.