This study was designed to compare prospectively the parameters of morbidity, cost, length of hospital stay, and fertility outcome after linear salpingostomy by laparoscopy versus laparotomy. Entry criteria included stable vital signs, hematocrit greater than 30%, age over 18 years, and desire for future fertility. All patients underwent diagnostic laparoscopy. Sixty patients with unruptured ectopic gestations of 5 cm or smaller were randomized to either laparoscopy (N = 30) or laparotomy (N = 30). Postoperative follow-up included serial measurements of serum beta-hCG titers at 3-day intervals and hysterosalpingography at 12 weeks. The laparoscopy and laparotomy groups were similar in age, height, weight, gravidity, gestational age, hematocrit, ectopic pregnancy size, and preoperative beta-hCG levels. The estimated blood loss was significantly (P less than .001) lower in patients undergoing laparoscopy, and was not affected by vasopressin injection. Two patients in the laparoscopy group required laparotomy for hemostasis, and two patients undergoing laparotomy had wound infection. One patient in each group had persistent trophoblastic activity. Baseline serum beta-hCG levels and the rate and magnitude of postoperative beta-hCG decline were similar in both groups. The length of hospital stay was significantly (P less than .001) shorter after laparoscopic salpingostomy (1.4 +/- 0.1 days) than after laparotomy (3.3 +/- 0.2 days). Postoperative hysterosalpingography showed patency of the involved tube in 16 of 20 (80%) and 17 of 19 (89%) of patients in the laparoscopy and laparotomy groups, respectively. Pregnancy rates were ten of 18 (56%) and 11 of 19 (58%) in these groups, respectively, and all pregnancies were conceived within 6 months of surgery.(ABSTRACT TRUNCATED AT 250 WORDS)