Purpose of Review <p>Persistent pain, stiffness, or suspected infection following shoulder arthroplasty remains a challenging clinical problem. Arthroscopy has emerged as a minimally invasive diagnostic and therapeutic tool in selected patients with painful anatomic total shoulder arthroplasty, reverse shoulder arthroplasty, or hemiarthroplasty. This review summarizes the current evidence regarding indications, outcomes, complications, and technical considerations for arthroscopy in the setting of pain following prior shoulder arthroplasty.</p> Recent Findings <p>Shoulder arthroscopy after arthroplasty has been described for glenoid component loosening, polyethylene wear, rotator cuff pathology, biceps tendon disease, postoperative stiffness, impingement, and suspected periprosthetic joint infection. Reported outcomes suggest that arthroscopy may improve pain and function in selected patients, particularly after glenoid component removal, biceps procedures, capsular release, and lysis of adhesions. Arthroscopic tissue biopsy also demonstrates greater diagnostic utility than aspiration or serum inflammatory markers for suspected periprosthetic shoulder infection. Technical strategies, including initial subacromial evaluation and controlled glenohumeral entry through the rotator interval, may reduce iatrogenic implant damage during arthroscopic evaluation.</p> Summary <p>Arthroscopy can be both diagnostic and therapeutic in well-selected patients with painful or stiff shoulder arthroplasty. Although it is not a substitute for revision surgery in cases of clear implant failure, instability, or massive cuff insufficiency, it may help clarify the diagnosis, treat focal pathology, and delay or avoid open revision in selected patients.</p>