Vitamin A derivative all-transretinoic acid (ATRA) has been reported to improve the outcome in patients with acute promyelocytic leukemia (APL). Retinoic Acid Syndrome (RAS) is a complication that has been noted to occur during the treatment of APL with ATRA. It is a clinical syndrome consisting of a constellation of signs and symptoms. In a patient with APL on ATRA, the diagnosis of RAS can be made based upon the presence of three of the following features: Fever, dyspnea, weight gain, hypotension, renal failure, pulmonary infiltrates, pleural effusion, and pericardial effusion. Pulmonary manifestations, especially pulmonary edema, are the most common presentation. Incidence of this adverse effect ranges from 6% to 27%. The pathogenesis of this complication is not completely understood. It can be potentially life threatening if not promptly recognized and treated. We report a case of retinoic acid syndrome in a young male with APL being treated with ATRA.