Patient's fall is classified into adverse events and it is one of the indicators of patient safety and an indicator of the quality of health care, but also the most commonly reported adverse event in healthcare institutions. Fall prevention programs and patient-related research in healthcare institutions are the focus of international nursing care and a modern, evidencebased healthcare approach. This study presents the results of a retrospective study of 77 patient falls at the Department of Intensive Cardiac Care, Arrhythmias and Transplant Cardiology, Clinical Hospital Center Zagreb, in the period from 01/01/2010 to 12/31/2018. The purpose of the study was to identify the critical factors for the fall, time, location, causes and consequences of falls with respect to fall risk and fall category by Janice Morse's fall categorization system. At admission to the hospital, the risk of a fall is evaluated and patients are classified into three risk categories: high, moderate and low. Given the risk factors and the cause of the fall, falls are categorized into accidental fall, expected physiological, and unexpected physiological fall. The hypotheses raised in this study are to determine the effect of lowered serum sodium as a predictor of a fall in the category of unexpected physiological fall and the existence of a negative relation between the patient's age and day of fall. Based on the collected data, a statistical analysis was performed and the following data were obtained: the Chi-square test of independence did not show a statistically significant relation ( 2 = 1.033, P = 0.597) between the decreased serum sodium level and the unexpected physiological fall. However, Phi is 0.112 and, according to Koen's criterion, there is a little influence of sodium level on the fall category in this research. The Spearman correlation coefficient found a negative relation (P = 0.038) between patient's age and day of fall from admission to the hospital treatment.