Osteochondroma is the most common benign bone tumor, but it rarely arises from the scapula. Scapulothoracic bursitis is quite rare and osteochondroma is one of the unusual causes of this condition. Synovial chondromatosis may occur extremely uncommonly in this bursa. We reported an unusual case of scapulothoracic bursitis with synovial chondromatosis, which is caused by osteochondroma. To the best of our knowledge, there is no defined chondromatosis in the scapulothoracic bursa secondary to scapular osteochondroma in the literature.