Hydroxyurea (HU) is a chemotherapeutic agent used for the treatment of myeloproliferative disorders such as chronic myeloid leukemia, polycythemia vera, and essential thrombocytosis. We describe a 69-year-old man who had essential thrombocytosis and developed amyopathic dermatomyositis after long-term HU therapy. He presented with Gottron papules and heliotrope erythema. The former has been described in all cases of HU-induced dermatomyositis; the latter has been seen in a few cases of that disorder.