Degree of Alarm Fatigue and Mental Workload of Hospital Nurses in Intensive Care Units.This study aimed to determine the degree of alarm fatigue and mental workload of ICUnurses, and to clarify the relationship between these two variables. A cross-sectional, descriptiveresearch design was used. Data were collected from 90 nurses working in four ICUs in Seoul, Republicof Korea, using a questionnaire determining their degree of alarm fatigue and mental workload.Data were collected from 6 March to 26 April 2021 and were analyzed using at-test, ANOVA, andPearson’s correlation coefficient. The average alarm-fatigue score was 28.59 out of 44. The item withthe highest score was “I often hear a certain amount of noise in the ward”, with a score of 3.59 out of4. The average of the mental workload scores was 75.21 out of 100. The highest mental workloaditem was effort, which scored 78.72 out of 100. No significant correlation was found between alarmfatigue and mental workload. Although nurses were consistently exposed to alarm fatigue, this wasnot directly related to their mental workloads, perhaps owing to their professional consciousnessas they strived to accomplish tasks despite alarm fatigue. However, since alarm fatigue can affectefficiency, investigations to reduce it and develop appropriate guidelines are necessary. This studywas not registered.