We report our experience with transvaginal sonography (TVS) in 35 nonpregnant adolescent and young teenage females referred for pelvic sonography. We assessed the efficacy of TVS as compared to transabdominal sonography (TAS) in 40 examinations. Of the 40 examinations, there were 5 discrepancies. In 4, abnormalities were detected on TVS not seen on TAS. In one there was a false-positive TAS with bowel recognized as such on TVS. Image quality (clarity, completeness, anatomic detail) was judged better by two reviewers on TVS in 85% of cases but additional useful information given in 58% of patients. TVS provided greater diagnostic confidence in 30% of patients with possible PID by better demonstration of fluid in the endometrial canal, pyosalpinx or tubo-ovarian abscess, or by better characterization of free pelvic fluid. The average scan time required for TVS was 8 minutes. TVS was better tolerated than TAS in the majority of patients. TVS is a relatively easy, rapid imaging technique that is well tolerated. It enhances anatomic detail and helps to elucidate unclear findings on TAS. TVS is also helpful in obsese patients and those unable to maintain a full bladder. It should be considered a useful and worthwhile adjunct to TAS in the evaluation of adolescent and teenagers with pelvic diseases.