Interruptions in nursing activities are a known patient safety concern, particularly around medication administration. Most studies describing this relationship are based on self-reported experiences, surveys, or retrospective analysis of voluntary reports. This study directly observed nurses during medication administration and discovered that each interruption was associated with a 12.1% increase in procedural failures and a 12.7% increase in clinical errors. Interruptions occurred in more than 50% of administrations with error severity increasing with interruption frequency. An alarming finding was that administration without interruptions still generated a procedural failure rate of nearly 70% and a clinical error rate of 25%. The latter findings are discussed further in an invited commentary [see link below] that advocates for greater efforts to improve the medication administration process, including protected times for these activities.