Clinicians caring for patients infected with Ebola virus must be familiar not only with screening and infection control measures but also with management of severe disease. By integrating experience from several Ebola epidemics with best practices for managing critical illness, this report focuses on the clinical presentation and management of severely ill infants, children, and adults with Ebola virus disease. Fever, fatigue, vomiting, diarrhea, and anorexia are the most common symptoms of the 2014 West African outbreak. Profound fluid losses from the gastrointestinal tract result in volume depletion, metabolic abnormalities (including hyponatremia, hypokalemia, and hypocalcemia), shock, and organ failure. Overt hemorrhage occurs infrequently. The case fatality rate in West Africa is at least 70%, and individuals with respiratory, neurological, or hemorrhagic symptoms have a higher risk of death. There is no proven antiviral agent to treat Ebola virus disease, although several experimental treatments may be considered. Even in the absence of antiviral therapies, intensive supportive care has the potential to markedly blunt the high case fatality rate reported to date. Optimal treatment requires conscientious correction of fluid and electrolyte losses. Additional management considerations include searching for coinfection or superinfection; treatment of shock (with intravenous fluids and vasoactive agents), acute kidney injury (with renal replacement therapy), and respiratory failure (with invasive mechanical ventilation); provision of nutrition support, pain and anxiety control, and psychosocial support; and the use of strategies to reduce complications of critical illness. Cardiopulmonary resuscitation may be appropriate in certain circumstances, but extracorporeal life support is not advised. Among other ethical issues, patients' medical needs must be carefully weighed against healthcare worker safety and infection control concerns. However, meticulous attention to the use of personal protective equipment and strict adherence to infection control protocols should permit the safe provision of intensive treatment to severely ill patients with Ebola virus disease.