Lesions of the mid-shaft of the humerus presenting as shoulder capsulitis. We describe three patients who presented with pain and restriction of movement at the shoulder suggestive of capsulitis, but proved to have lesions of the mid-shaft of the humerus. It is important to be aware of the possibility of this cause of a 'frozen shoulder', since radiographs of the shoulder are usually cropped at the mid-humerus and lesions at this level may easily be missed. A radiograph of the entire humerus, or an isotope bone scan, may be more useful than repeated shoulder radiographs in patients whose shoulder symptoms do not respond to standard treatment. 