Checklists have contributed to some of the most effective patient safety interventions to date, including the landmark Keystone ICU program that nearly eliminated catheter–associated bloodstream infections and the surgical safety checklist that reduced mortality. More recently, checklists have failed to yield improvements in some settings, highlighting that successful programs rely on many external and internal factors beyond checklists. This randomized clinical trial studied the effect of introducing a daily checklist, goal setting, and clinician prompting in intensive care units in Brazil. This robust bundled intervention did not reduce in-hospital mortality. The intervention group showed some improvements in a few process measures, such as use of low tidal volumes, central venous catheters, and urinary catheters, but there was no difference in secondary clinical outcomes. This study adds to the current controversy over the efficacy of checklists for improving patient safety outcomes.