In this second part of the series on dermatomyositis, the diagnosis and its criteria with review of autoantibodies, capillaroscopy, imaging exams, histopathology, muscle biopsy, electroneuromyography, and muscular enzymes will be assessed. The association with malignancy, since it is described as paraneoplasic, will be discussed. The different therapeutic options for this disease will also be reported, including for dystrophic calcification, a rare and late complication of dermatomyositis.