Sonographic signs were correlated with clinical data, surgical findings, and pathology in 15 patients withtubal pregnancy. Sonograms showed absence of intrauterine gestation in 12 patients. In 3, structures resembling gestational sacs were produced by decidual reaction and blood in the uterine cavity separating the endometrial echoes. The uterus was normal in size in 6 cases. Almost all sonograms showed a pelvic mass (usually adnexal) displacing the uterus. Seven patients had predominantly sonolucent masses, 3 had complex masses, and 4 had both types. Only one woman exhibited a definite gestational sac in an extrauterine location. Four patients had a negative pregnancy test at the time of sonography. Meticulous sonographic technique and a high index of suspicion will facilitate the diagnosis of tubal pregnancy in most cases.