Dermatomyositis in pregnancy is rare. Pregnancy may be a precipitating factor at the onset or may develop during the course of dermatomyositis, which would exacerbate disease activity. In this study, we report a 22-year-old female patient who developed generalized skin rash and progressive muscle weakness in the twelfth week of pregnancy. She was diagnosed with dermatomyositis and underwent therapeutic abortion, due to the high fetal mortality rate of the disease when developed in the first trimester. Her symptoms improved with treatment of intravenous immunoglobulin and a high dose of corticosteroids.