A strong and often polarized debate has taken place during recent years concerning the consequences of dehydration in the terminally ill patient. When a patient has a severely restricted oral intake or is found to be dehydrated, the decision to administer fluids should be individualized and made on the basis of a careful assessment that considers problems related to dehydration, potential risks and benefits of fluid replacement, and patients' and families' wishes. This review discusses the assessment of hydration status in the terminal cancer patient and the options for fluid administration in the cases where evaluation of the patients' condition has led to this indication. These include different modes of hypodermoclysis, intravenous hydration, use of the nasogastric route, and proctoclysis. Arguments for and against rehydration have been previously addressed by other authors and fall outside the scope of this review.