Optimal recovery of the critically ill elderly patient depends on an adequate nutritional state. Preventing and treating malnutrition is fundamental to the provision of good patient care, yet providing nutritional support to the critically ill elderly is challenging. Health care has not reached the state of sophistication in which a few simple rules suffice. Many of the current assessment techniques, diagnostic standards, and guides for intervention are based on studies of the young and middle aged. As the critically ill elderly population continues to grow, more specific assessment parameters need to be identified so that the elderly person's response to different nutritional therapies will be understood better. Carefully documented and published case studies will enrich the understanding of nutritional support in this vulnerable group of patients.