The main indication for arthroscopic procedures in the posterior compartment of the ankle joint are osteochondral defects in the posterior one third of the talus and osteochondral defects in the posterior tibial plafond. Other indications are removal of loose bodies, treatment of synovial chondromatosis, reduction of posterior tibial RIM osteophytes, and treatment of avulsions of the posterior talofibular ligament (PTFL). More seldom indications include the treatment of a Cedell fracture (Chap. 16) and treatment of posterior impingement after total ankle prosthesis. These indications are mentioned in this chapter. Finally this chapter mentions the treatment of total synovectomy.