As the prevalence of cancer continues to increase in the general population and improvements in cancer treatment prolong survival, the incidence of patients presenting to the emergency department with oncologic complications will, similarly, continue to rise. This issue reviews 3 of the more common presentations of oncology patients to the emergency department: metastatic spinal cord compression, tumor lysis syndrome, and febrile neutropenia. Signs and symptoms of these conditions can be varied and nonspecific, and may be related to the malignancy itself or to an adverse effect of the cancer treatment. Timely evidence-based decisions in the emergency department regarding diagnostic testing, medications, and arrangement of disposition and oncology follow-up can significantly improve a cancer patient's quality of life.