The present paper reports on 21 tubal pregnancies which have occurred after tubal sterilization in Tübingen or elsewhere since 1975. The proportion of tubal pregnancies amongst sterilization failures was 75%. The interval between sterilization and the occurrence of the tubal pregnancy ranged between 5 months and 7-3/4 years. The most frequent symptoms of the tubal pregnancies were pain (15/21), amenorrhea (11/21) and vaginal bleeding (5/21). Only 11 of the 21 patients were admitted to the clinic with the (suspected) diagnosis of an extra-uterine pregnancy. In 20 of the 21 patients the pregnancy was located in the distal (ampullar) segment of the tube; in 8 cases the tube was ruptured. Thirteen patients were treated by bilateral and 5 by unilateral salpingectomy, and a further 3 by unilateral adnexectomy. Summarizing, a considerable number of pregnancies occurring after unsuccessful tubal sterilization are extra-uterine. They are often not recognized, or only at a late stage. In the authors' view the patient should be informed of the possibility of a tubal pregnancy prior to sterilization.