Direct posterior and posterolateral portals are the standard portals used in posterior elbow arthroscopy. A posteromedial portal in the elbow is not recommended because of its proximity to the ulnar nerve. However, iatrogenic injuries to the ulnar nerve have been reported after elbow arthroscopy using the standard posterior portals, especially in posteromedial elbow joint pathologies. We present a surgical technique applicable to posteromedial elbow pathology by using ultrasound-assisted posteromedial portal placement of the elbow joint. Through this technique, the position of the ulnar nerve is identified prior to portal creation and the instruments are introduced from an ulnar to radial direction, thus avoiding ulnar nerve injury.