In recent years, there have been notable advancements in the critical care, including significant progress in medical knowledge, technological innovations, and the development of clinical expertise crucial for effectively treating patients. Numerous factors play a role in shaping the admission and discharge decisions made in the context of intensive care units. In this research we aimed to evaluate the effect of the time of the intensive care unit admissions, categorized as either "off hours" or "business hours," on the subsequent death rates among patients. We performed a retrospective investigation of the mortality rates of 1605 patients in intensive care unit between 2007 and 2010. We included all admissions to the intensive care unit without applying any exclusion criteria. The primary outcome measures in our study were the timing of admission, as well as the rates of discharge and mortality. "Business hours" denoted the time frame from 8:00 to 16:59 on weekdays, while "off hours" encompassed the period from 17:00 to 07:59 on weekdays and throughout the weekends. Significantly reduced mortality rates were evident among patients admitted on Mondays and Wednesdays in comparison to those admitted on other days (p=0.037 and p=0.045, respectively). Furthermore, the study revealed an elevated risk of mortality for admissions during weekends when compared with those admission on weekdays (p=0.005). The results found that a significant association was present between admission timing and mortality. Patients admitted on weekends and during off-hours exhibit an increased risk of mortality when compared to those admitted on weekdays during business hours. Keywords: Intensive care unit, Mortality rate, Time of admission