Dermatomyositis is an idiopathic inflammatory myopathy with characteristic cutaneous manifestations. The association between dermatomyositis and malignancy is becoming more clearly delineated. A sort of dermatomyositis is thought to be paraneoplastic syndrome and dermatomyositis may follow clinical course of malignancy. We report a 68-year-old woman with dermatomyositis, whose clinical onset of dermatomyositis was apparently concomitant with breast cancer. Dermatomyositis had settled down and oral steroid could be tapered after the resection of breast cancer. Creatine kinase value was elevated before the detection of the first and second recurrence and in the terminal state. At the second recurrence, skin lesions and creatine kinase value had flared up and immediate metastatic check-up revealed the recurrence. Our case shows dermatomyositis, which was thought to be paraneoplastic syndrome, that followed clinical course of malignancy and suggests immediate check-up is needed for early detection of recurrence when dermatomyositis flares up after the resection of the malignancy.