Overuse or structural bony abnormalities of the scapulothoracic “articulation” make it susceptible to chronic friction, which can lead to bursitis and soft tissue changes. Clinically, scapulothoracic bursitis is associated with pain, crepitus, and scapular snapping. On physical examination, a firm, large subscapular mass may be present, sometimes with rapid growth. Asymptomatic cases without scapular snapping can be clinically indistinguishable from soft tissue tumors of the chest wall. Characteristic imaging findings of scapulothoracic bursitis include a well-circumscribed cystic mass, internal debris, and intralesional hemorrhage. Recognition of these characteristic findings is essential to avoid misinterpretation and unnecessary treatments. Here, we describe a case of an incidentally discovered, asymptomatic, fluorodeoxyglucose (FDG)-avid subscapular mass with typical imaging features of scapulothoracic bursitis. Additional imaging and histopathologic examination of sampled tissue confirmed the diagnosis. To our knowledge, this incidental finding is the first documented case of FDG-avid scapulothoracic bursitis.