Intensive care unit (ICU) patients are vulnerable from a patient safety standpoint, with hospital-acquired infections and medication errors being particularly common examples of adverse events (AEs). This cohort study analyzed AEs in more than 3,600 ICU patients and assessed the relationship between AEs and mortality. The overall incidence of AEs was extraordinarily high, with one in three patients experiencing at least one AE. Multiple AEs, particularly hospital-acquired infections, were independently associated with mortality. While improving safety in the ICU remains a major challenge, recent research has documented remarkable successes in preventing one of the most common AEs, catheter-related bloodstream infections.