Checklists have been long used as a cognitive aid in various high-stakes environments to improve the reliability and performance of individuals and teams. When designed well, implemented thoughtfully, and monitored closely, they offer the opportunity to improve the performance of health care teams and advance patient safety. There are different types of checklists; examples include task lists, troubleshooting lists, coordination lists, discipline lists, and to-do lists. Each is useful in different situations and requires different implementation strategies. Checklists also are different from algorithms, care maps and protocols, and educational tools. Therefore, they are not useful in all situations. In appropriate selected clinical circumstances, checklists are tools that can help standardize care, improve communication, and help teams perform optimally.