Cervical cerclage is a common surgical technique that has been used for more than 50 years to prevent preterm deliveries and in the management of a threatened second trimester loss. However, it remains one of the most controversial interventions in obstetrics and this is probably due to difficulties in diagnosing cervical insufficiency, which is based on a history of recurrent second trimester loss or early preterm delivery following painless cervical dilatation in the absence of contractions or bleeding. This article reviews in 2008 the current literature regarding the efficacy of elective cerclage, ultrasound-indicated cerclage, emergency cerclage, and cervico-isthmic cerclage for singletons and multiple pregnancies.