The evolution of hydroxyurea as a chemotherapeutic agent has been unique. Hydroxyurea inhibits synthesis of DNA, has antitumor activity, and is myelosuppressive. It has attained a significant role in the management of chronic myelogenous leukemia. A nonrandomized comparison of busulfan and hydroxyurea concluded that hydroxyurea was the preferable agent in the treatment of chronic myelogenous leukemia and was associated with less life-threatening toxicity. Because of its systemic effects, hydroxyurea is also used in the treatment of polycythemia and psoriasis.