From 1982–1986, 625 tubal ectopic pregnancies were treated at the University of Hawaii School of Medicine Affiliated Hospitals. The percentage of cases in which the involved tube was preserved increased from 7% in 1982 to 26% in 1986. The presence of persistent trophoblastic tissue was diagnosed by elevated serum levels of the beta subunit of human chorionic gonadotropin (P-hCG) after conservative surgery in four patients. Three of the four patients developed intra-abdominal hemorrhage and required laparotomy. One patient remained asymptomatic despite elevated PhCG levels, which disappeared 60 days after surgery. Evaluation of histologic slides demonstrated persistent intraluminal trophoblastic tissue without invasion in two patients, and extraluminal invasion into the tubal wall in one patient. The use of postoperative serial PhCG titers might facilitate recognition of this complication in time to prevent further tubal damage and hemorrhage.