Background. Laparoscopic salpingostomy is a well-established treatment for patients with tubal pregnancy who desire to retain fertility. Another approach that preserves the fallopian tube is medical treatment. We compared systemic methotrexate and laparoscopic salpingostomy in the treatment of tubal pregnancy. Outcome measures were treatment success, tubal preservation, and homolateral tubal patency. Methods. Between January, 1994, and September, 1996, haemodynamically stable patients with laparoscopically confirmed unruptured tubal pregnancy and no signs of active bleeding were randomly assigned systemic methotrexate (four 1.0 mg/kg doses of intramuscular methotrexate alternated with 0.1 mg/kg oral folinic acid) or laparoscopic salpingostomy. Treatment success was defined as complete elimination of the tubal pregnancy (serum human chorionic gonadotropin < 2 IU/L) and preservation of the tube. Homolateral tubal patency was assessed by hysterosalpingography. Analysis was by intention to treat. Findings 100 patients were included in the trial. Of 51 patients allocated systemic methotrexate, 42 (82%) were successfully treated with one course; two (4%) patients needed a second course for persistent trophoblast. Surgical intervention was needed in seven (14%) patients; salpingectomy was necessary in five of these patients for tubal rupture. Of the 49 patients allocated laparoscopic salpingostomy, 35 (72%) were successfully treated by laparoscopic salpingostomy alone; salpingectomy was needed in four (8%) patients, and ten (20%) needed methotrexate for persistent trophoblast. The tube was preserved in 46 (90%) patients in the methotrexate group versus 45 (92%) in the salpingostomy group (rate ratio 0.98 [95% CI 0.87-1.1]). Homolateral tubal patency could be assessed in 81 patients: the tube was patent in 23 (55%) of 42 patients in the methotrexate group and in 23 (59%) of 39 patients in the salpingostomy group (rate ratio 0.93 [0.64-1.4]). Interpretation in haemodynamically stable patients with unruptured tubal pregnancy, systemic methotrexate and laparoscopic salpingostomy were successful in treating the majority of cases. We found no significant difference between the treatments in the homolateral patency rate. Subsequent fertility outcome has to be awaited to show which treatment yields better fertility prospects.