Debate continues about whether to withhold or withdraw intravenous, subcutaneous, or nasogastric hydration in the terminally ill. Nurses may be confronted with situations where the terminally ill patient or family must make a decision regarding hydration. Therefore, nurses must be knowledgeable about terminal dehydration literature and research. This article is a review of the literature on terminal dehydration. The focus is on the definition of terminal dehydration, physiological benefits and disadvantages of terminal dehydration, rationale for hydrating, review of research in terminal dehydration, physiological basis for comfort in the terminally dehydrated, and suggestions for research and practice.