AbstractAimThis study aimed to describe the circadian characteristics of hospitalized mortality in order to provide nursing guidance for preventing in‐hospital mortality.DesignA retrospective analysis on inpatient information was implemented.MethodsHarmonic Analysis of Time Series was applied to quantify the periodic structure of the frequency of the occurrence of death.ResultsA total of 3300 cases were included in the present study (male, 63.4% and median age 73 years), including 1540 (46.7%) ICU patients. Incidence of overall hospitalized death exhibited a circadian pattern, presenting peaks from 07:00 to 12:00 and 15:00 to 20:00 P.M., with 21.5% and 13.1% increase above the average at those peak points, respectively. Similarly, the incidence of sudden cardiac death (SCD) showed peaks between 06:00–12:00 and 15:00–20:00, with a 34.7% and 28.0% increase above the average at peak time, respectively. The distribution of death incidence revealed no statistical difference between SCD and non‐SCD (p= 0.525).