Cerclage was performed by us during the past 5 1/2 years in 71 women (0.68% of all births). In 23 women, cerclage was performed prophylactically and in 48 women as therapy of early maturing of the cervix. Cerclage was applied, mainly according to McDonald, between the 13th and 33rd weeks of pregnancy, maximum incidence of surgery occurring between the 17th and 27th week (63%). Cervical insufficiency is only temporarily removed by cerclage. After the suture has been removed, cervical dilatation should be variable. If this is not the case, the diagnosis of "cervical insufficiency" must be considered doubtful. This criterion was fulfilled in 83% of the therapeutic cases of cerclage compared with 43% in the prophylactic cases. Within 24 hours after removal of this suture, 39 patients (59%) had given birth. The prophylactically indicated cerclages often did not meet the criterion cervical dilatation uteri after removal of suture and rapid birth", whereas the majority of the therapeutic cerclages complied with the criterion. Our results are compared with those published in the literature. Despite the trend noticeable in literature towards a more liberal indication of cerclage, we will continue to perform this operation with discretion.