Several clinical practice guidelines focusing on nutrition therapy in mechanically ventilated, critically ill patients are available to assist busy critical care practitioners in making decisions regarding feeding their patients. However, large gaps have been observed between guideline recommendations and actual practice. To be effective in optimizing nutrition practice, guideline development must be followed by systematic guideline implementation strategies. Systematic reviews of studies evaluating guideline implementation interventions outside the critical care setting found that these strategies, such as reminders, educational outreach, and audit and feedback, produce modest to moderate improvements in processes of care, with considerable variation observed both within and across studies. Unfortunately, the optimal strategies to implement guidelines in the intensive care unit are poorly understood, with scarce data available to guide our decisions on which strategies to use. The authors identified 3 cluster randomized trials evaluating the implementation of nutrition guidelines in the critical care setting. These studies demonstrated small improvements in nutrition practice, but no significant effect on patient outcomes. There are some data to suggest that tailoring guideline implementation strategies to overcome identified barriers to change might be a more effective approach than the multifaceted "one size fits all" strategy used in previous studies. Adopting this tailored approach to guideline implementation in future studies may help bridge the current guideline-practice gap and lead to significant improvements in nutrition practices and patient outcomes.