Purpose: The purpose of the study was to examine the appropriate use of arrhythmia, ischemia, and QTc interval monitoring in the acute care setting. Methods: We analyzed baseline data of the Practical Use of the Latest Standards for Electrocardiography (PULSE) trial, a multisite randomized clinical trial evaluating the effect of implementing electrocardiographic monitoring practice standards. Research nurses reviewed medical records for indications for monitoring and observed if arrhythmia, ischemia, and QT interval monitoring was being done on 1816 patients in 17 hospitals. Results: Almost all (99%) patients with an indication for arrhythmia monitoring were being monitored, but 85% of patients with no indication were monitored. Of patients with an indication for ischemia monitoring, 35% were being monitored; but 26% with no indication were being monitored for ST-segment changes. Only 21% of patients with an indication for QT interval monitoring had a QTc documented, but 18% of patients with no indication had a QTc documented. Conclusion: Our data show evidence of inappropriate monitoring: undermonitoring for ischemia and QTc prolongation and overmonitoring for all 3 types of monitoring, especially arrhythmia monitoring. © 2010 Elsevier Inc. All rights reserved.