Monochorionic (MC) twin pregnancy is associated with special complications that are unique to the shared placenta and vascular anastomoses. These complications include twin-to-twin transfusion syndrome (TTTS), selective fetal growth restriction (sFGR), twin reverse arterial perfusion sequence (TRAPS), twin anemia-polycythemia sequence (TAPS), and conjoined twins [1]. Furthermore, the incidence of discordant structural anomalies is more common in MC twins (6–8%) than in dichorionic (DC) twins (1–2%). In these conditions, selective reduction of one of the MC twins may have to be considered to maximize the chance of survival of the co-twin, or to minimize the risk to it. Unlike DC twin pregnancies in which their placentas have no vascular anastomoses, MC twins are connected via multiple vascular channels between their fused placenta [2]. Therefore, intracardiac KCl injection is not a feasible option in MC twin pregnancies [3]. Hence selective reduction must aim specifically at stopping the target twin’s umbilical blood flow, either at the umbilical cord level, or at the intra-abdominal portion of its vessels just beneath its insertion site (intrafetal), using more sophisticated methods. In this chapter, various indications and different surgical methods of selective reduction, as well as the comparison between the methods, are discussed.