Thirty-four patients believed to have ectopic pregnancies were examined by transabdominal and transvaginal ultrasonography. Twenty-five patients had tubal pregnancy confirmed operatively within 24 hours after ultrasonographic examination. In these cases adnexal findings highly suspicious for ectopic pregnancy were found in 68% of cases by transabdominal ultrasonography and in 84% by transvaginal ultrasonography. A distinct adnexal gestational sac was apparent in 32% of cases by transabdominal ultrasonography and in 64% of cases by transvaginal ultrasonography. Transvaginal ultrasonography was significantly more accurate (p less than 0.01) in identifying an adnexal gestational sac and allows more detailed adnexal imaging.