Hyperleukocytosis in leukemia challenges physicians and nurses to provide swift and aggressive care to the patient so that complications from leukostasis are avoided. It is therefore prudent for nurses to recognize patients at risk for hyperleukocytosis. Prevention of complications is the key because once pulmonary and central nervous system symptoms arise the probability for reversal becomes uncertain. The major role of nurses caring for patients with hyperleukocytosis is to provide baseline assessment of pulmonary and neurological function, with continuous follow-up assessment to detect early signs and symptoms of organ dysfunction. Once complications from hyperleukocytosis are apparent, nursing interventions are aimed at easing respiratory distress, minimizing increases in intercranial pressure, and providing emotional support for the patient and his family.