The reliability of the preoperative history obtained from adolescent patients in ruling out pregnancy was prospectively evaluated. Four hundred forty-four patients who underwent 525 procedures were questioned preoperatively regarding the possibility of pregnancy. Regardless of the history, a urine pregnancy test was ordered in accordance with institutional practice. In 508 cases, patients denied the possibility of pregnancy. Eight patients stated that they might be pregnant, and in six cases the parents responded for the patients and denied the possibility of pregnancy. Seventeen patients were not tested due to patient/parent refusal (n = 9) or inability to void (n = 8). All pregnancy tests were negative except one that was questionably negative. This patient had denied the possibility of pregnancy and had been anesthetized prior to test results. Follow-up revealed that the patient was not pregnant. Our data demonstrate that the preoperative history obtained from adolescent patients at our institution regarding their pregnancy status was in agreement with pregnancy test results. We suggest that a detailed history regarding last menstrual period, contraception, sexual activity, and the possibility of pregnancy be obtained in all postmenarchal patients presenting for surgery. Although in other populations history and pregnancy testing did not agree 100% of the time, for our adolescent population, human chorionic gonadotrophin (HCG) testing appears to be necessary only if indicated by patient history.