Leukostasis is a complication of acute myeloid leukemia. It is associated with hyperleukocytosis and a poor prognosis. The organs primarily affected are the central nervous system and lung. The presence of pulmonary leukostasis has been associated with a lower survival rate. Its recognition can be difficult because it can mimic the presence of infections and bleeding complications associated with acute leukemia. We present the case of a patient with hyprleukocytosis with pulmonary and cerebral involvement (Acta Med Colomb 2011; 36: 90-92).