Aim: Dermatomyositis is a rare, idiopathic inflammatory myopathy that affects multiple organ systems and may ultimately be fatal. Classical signs and symptoms include progressive muscle weakness, cutaneous rashes, and calcinosis; however, the clinical presentation of the disease is variable and may be mistaken for other autoimmune disorders. We present the first published case of a patient diagnosed with dermatomyositis who developed calcifications within the periodontal ligaments of multiple teeth. Material and methods: A 46-year old female previously diagnosed with dermatomyositis and generalized severe periodontitis was found to have numerous calcifications within the periodontal ligaments of mandibular and maxillary teeth. Results: The histopathology of biopsied lesions showed spherical calcifications within the periodontal ligaments with minimal inflammatory response. The calcifications were radiopaque lesions distinct from dental calculus. Conclusion: Dental professionals who detect periodontal ligament calcifications or other signs of dermatomyositis through clinical or radiographic examination should refer the patient for further diagnostic testing to prevent severe morbidity and possible mortality.