Abstract Thirty women who had a small unruptured tubal pregnancy were treated by laparoscopically guided injection of prostaglandin F 2α into the oviduct and into the corpus luteum. They had no side effects. The serum human chorionic gonadotropin (S-HCG) concentration decreased in 25 women to < 20 IU/l in a median time of 8 days (range 1–45). Five women were operated on because of increasing S-HCG concentration. The median diameter of the oviduct at the site of the gestation, the tubal localisation and the gestational age was similar in the women treated by prostaglandin and those, who were operated on after failure of the procedure. Four of the 6 women, with S-HCG concentrations of more than 2000 IU/l, needed subsequent operative treatment, compared to only one of 24 with a lower concentration. The median duration of the hospital stay after treatment was 2 days for the group of women with a S-HCG concentration of less than 2000 IU/l. Hysterosalpingography 3 months after treatment showed patency on the side of the pregnancy in 12 of 14 women. Prostaglandin injection seems to be an appealing option for the treatment of selected ectopic pregnancies.