Over the decades, arthroscopy has grown in popularity for the treatment of many foot and ankle pathologies. While anterior ankle arthroscopy is a widely accepted technique, posterior ankle/subtalar arthroscopy is still a relatively new procedure. The goal of this review is to outline the indications, surgical techniques, and results of posterior ankle/subtalar arthroscopy. The main indications include: 1) osteochondral lesions (of subtalar and posterior ankle joint); 2) posterior soft tissue or bony impingement; 3) os trigonum syndrome; 4) posterior loose bodies; 5) flexor hallucis longus (FHL) tenosynovitis; 6) posterior synovitis; 7) subtalar (or ankle) joint arthritis; 8) posterior tibial, talar, or calcaneal fractures (for arthroscopic reduction and internal fixation). Although posterior ankle/subtalar arthroscopy has shown to be safe and effective in the treatment of many of the above mentioned conditions, thorough knowledge of the anatomy, correct indications, and a precise surgical technique are essential to produce good outcomes.