The introduction of information technology (IT) has transformed health care, but it is clear that the rapid uptake of IT has profoundly changed clinician workflow, resulting in unintended consequences that in some cases have harmed rather than helped patients. These unintended consequences include new types of errors resulting from computerized provider order entry, alarm fatigue arising from the proliferation of well-intended safety alerts, and problems with poor interoperability of different electronic medical record systems. The Joint Commission issues sentinel event alerts periodically to highlight emergent safety issues, and this alert describes some of the 120 sentinel events reported to The Joint Commission since 2003 that were determined to be related to IT. Several recommendations to prevent IT–related safety threats are discussed, including improving safety culture by creating a shared sense of responsibility between users and developers, paying careful attention to safe IT implementation, and engaging leadership to provide oversight in health IT planning, implementation, and evaluation. The hazards and benefits of health IT are the subject of a recent book by a prominent patient safety expert.