All-trans-retinoic acid (ATRA) is a differentiation agent which can induce complete remission in a majority of patients with acute promyelocytic leukemia (APL). Unfortunately, about one-fourth of patients thus treated may develop potentially fatal complications, including respiratory distress, fever, pericardial and pleural effusion, renal failure and hypotension which constitute the retinoic acid syndrome (RA syndrome). We report one APL patient, who presented with leukocytosis and subacute disseminated intravascular coagulopathy, and developed RA syndrome during treatment with ATRA.