The reproductive history of 19 women with a diagnosis of unicornuate uterus confirmed by laparoscopy or laparotomy is analyzed. The patients were followed for 2 to 10 years. One patient had a cavitary communicating rudimentary horn, four a cavitary noncommunicating rudimentary horn, seven a noncavitary rudimentary horn, and seven no rudimentary horn. Six of the patients presented with primary infertility. The other 13 women had a total of 29 pregnancies, 1 (3.4%) in a rudimentary horn determining rupture; abortions occurred in 17 (58.6%), premature labor in 3 (10.3%), and term births in 8 (27.6%), with a live birth rate of 38%. Of the 11 births, 6 (54.5%) were breech presentations, and 9 (81.8%) were cesarean sections. In five cases the rudimentary horn was removed, with associated salpingooophorectomy in three patients. Cervical cerclage was not performed in any of the patients.