Alarm fatigue, in which clinicians ignore safety alerts if they are too frequent or perceived to be clinically irrelevant, can lead to lack of awareness of an unsafe situation. This concern is particularly acute in intensive care units where patients are typically monitored with multiple devices, each with alarms. This retrospective review examined all alarm data regarding physiologic monitoring, including electrocardiogram, blood pressure, and oxygenation, from five intensive care units in a medical center. The vast majority of alarms were false-positives. Inappropriate alarm settings, electrode failure leading to poor signal quality, and alerts for non-actionable events were common causes for unnecessary alarms. The authors call for improving device design and monitor algorithms in order to reduce alarm fatigue. A previous AHRQ WebM&M perspective discussed the safety of medical devices.