Conjoined twins are very rare congenital malformation. The aim of this study was to summarize our experiences of surgical separation on seven sets of conjoined twins, and improve the treatment of conjoined twins in the future. A retrospective review of surgical separation included data of prenatal diagnosis, associated malformation, timing of separation, intra- and postoperative management, and follow-up of six sets of conjoined twins at Shanghai Xin-Hua Hospital from 1980 to 2005 and one set at Shanghai Children's Hospital in 2002. Surgical separation was performed on seven sets of conjoined twins; six sets of thoracopagus-omphalapagus (including four sets of xipho-omphalopagus) and one set of ischiopagus. All sets presented varying degrees of severity of congenital cardiac malformations. Four sets were diagnosed prenatally by ultrasonography. Two sets of conjoined twins (case 2 and case 3) required emergent separation within 7 days after birth; both members of case 2 died within 2 days post operation, one member of case 3 died during operation while the other member survived. Five sets had scheduled separation undertaken more than 30 days after birth. One member of a set (case 6B) died 13 days after operation due to severe congenital cardiovascular anomalies. All other members of conjoined twins survived. Case 6A had a severe defect of the anterior thoracic cage and prosthesis of titanium alloy scaffold filled with silicone rubber was used to repair the defects successfully. Following up from 1980 to 2005, one member of a set (case 1A) died 4 years after operation due to pneumonia. Contact was lost to the surviving member of case 3 (ischiopagus). Other survivors of the separations had normal development. (1) Timing of operation and separation plan should be given according to the circumstances and the nature of the organ shared in each individual set of twins. (2) Prosthesis of titanium alloy scaffolds filled with silicone rubber may become one of viable methods for repairing severe defects of the thoracic cage.