During a 3-year period, 525 women referred to our department with abdominal pain and/or vaginal bleeding in the first trimester of pregnancy were evaluated by transvaginal sonography. Ectopic pregnancy was suspected and laparoscopy done when sonography showed an empty uterus or pseudosac together with free pelvic fluid and/or a tubal mass. Fifty-seven patients fulfilled these criteriae. Among these patients, sonography showed an empty uterus in 48, pseudosac in five, a non-diagnostic intrauterine echo in four, a tubal mass in 45 and free pelvic fluid in 54. Laparoscopy confirmed ectopic pregnancy in 53 patients (93.0%). There were only five tubal ruptures. Pelvic blood was found in all of the 54 patients with free fluid on sonography; i.e. in 51 of 53 patients with ectopic pregnancy and in three with miscarriage. Forty-nine patients with ectopic pregnancy were managed by laparoscopy and four by laparotomy. All were hemodynamically stable. The diagnostic sensitivity and specificity of vaginal sonography for ectopic pregnancy was 96.2% and 99.4%, respectively, for the finding of free pelvic fluid, and 81.1% and 99.6% for a tubal mass. All patients with ectopic pregnancy were correctly selected for laparoscopic management. Transvaginal sonography is a valuable tool in the early diagnosis of ectopic pregnancy.