Malnutrition is associated with increased morbidity and mortality and is common in patients admitted to hospital. Nutritional status is not routinely assessed on admission, and nutritional depletion escapes recognition in the majority of affected patients. Nutritional status declines during hospital stay, and this trend is most marked in patients who are already malnourished on admission. Techniques for nutritional support are available, their appropriate use leads to improved nutritional status and clinical outcome in most patients. There is evidence that the current use of artificial nutrition is suboptimal and associated with a high complication rate. The introduction of clinical guidelines and the formation of nutrition support teams will improve nutritional management in the future. The development of new substrates and 'pharmaconutrition' is likely to further improve the outcome for many patients. There will remain a need for more studies to define the cost efficacy of artificial nutrition across a broad spectrum of clinical practice.