An increasing percentage of patients with uterine leiomyomas was observed in the Department of Obstetrics, University of Freiburg, on comparing the years 1970-79 (0.25%) and 1980-89 (0.64%). While first trimester bleeding, pain and premature labour, being typical obstetrical complications, were encountered in a comparable frequency, atonic bleeding was observed more often during the nineteen-eighties. Pain and premature labour were often present, if the leiomyomas were large, irrespective of both their number or localization. Atonic bleeding was observed more frequently, if large leiomyomas were present. A correlation between the presence of uterine leiomyomas and placental deficiency, premature birth, and EPH gestosis seems uncertain. The total complication rate among all pregnant patients with uterine leiomyomas was 65% from 1980-89. The Caesarean section rate among patients with uterine leiomyomas increased during the evaluated time span, and reached 51% during the 1980's, as compared to a general frequency of Caesarean sections of 19% during the latter time period; this increase in frequency seems to be rather in keeping with a generally increasing Caesarean section rate as opposed to a changing indication for surgery in patients with myomas. The myomas themselves caused Caesarean sections in 50% of cases, while in the remaining 50% of patients, Caesarean sections were performed for general obstetrical reasons. The probability to be delivered by Caesarean section was especially high amongst patients with multiple myomas or with an isthmic myoma. Our study supports a conservative approach in the case of pregnancy and uterine leiomyomas.