Critical care in low-income countries remains rudimentary. When defined as all aspects of care for patients with sudden, serious, reversible disease, critical care is not disease or age specific and includes triage and emergency medicine, hospital systems, quality of care and Intensive Care Units. This review collates the literature on critical care in low-income countries and explores how the care can be both feasible and effective. Emergency care including triage is often one of the weakest parts of the health system; but if well organized it can be life-saving and cost-effective. Emergency triage and treatment has been developed for paediatric admissions with promising results. Hospital systems do not currently prioritize the critically ill and few hospitals have Intensive Care Units. The quality of care given to inpatients on hospital wards is often poor and could be improved in many ways. There is a lack of training and awareness of the principles of critical care. Basic critical care concentrating on ABC - airway, breathing and circulation - need not be resource intensive. Oxygen is a cheap and effective treatment for pneumonia and other severe disease, but is not always available. Improved critical care could have a significant effect on the burden of disease and effects of ill health. Research into the most cost-effective treatments and methods of caring for critically ill patients is urgently needed.