This study in the Health Affairs patient safety theme issue examines the implementation of surgical safety checklists. Checklists have been shown to improve patient outcomes in randomized control trials, but implementation studies have not consistently demonstrated similar improvements. In this statewide initiative, implementation of the checklist varied significantly among sites. Factors associated with more successful implementation included greater leadership participation, frontline engagement, and more frequent activities for all involved groups, including surgeons, nurses, technicians, and administrators. Sites that invested more funding and time also saw greater checklist implementation. The authors conclude that hospitals that participated more did better. Past PSNet interviews with Lucian Leape and David Urbach discussed their perspectives on surgical safety checklists.