Aim: Frailty can be defined as reduced resistance capacity against the environmental stresses due to a cumulative decline in the physiological reserves of the subject. Clinical Frailty Scale (CFS) can be used to measure frailty. We aimed to calculate the prevalence of frailty in patients admitted to intensive care unit (ICU) and analyze some general features of those patients.Material and Methods: The study was conducted in general ICUs of a state hospital. Patients who were admitted between January 2016 and March 2018 were analyzed retrospectively. Demographic characteristics, “Clinical Frailty Scale” (CFS) score, clinical data and other patient results were recorded. Subsequently, patients were divided into two groups as frail (CFS≥5) and non-frail (CFS<5) and then statistically compared.Results: A total of 1139 patients were included in the study. The frailty rate of patients aged 50 years and over was 54.7%. The median age of the frail group was significantly higher (78 vs 69 year; p<0,0001). APACHE II, mechanical ventilation rate, and length of ICU stay were significantly higher in the frail group (25 vs 22; p<0,0001 ve 69,8% vs 52%; p<0,0001 ve 14 vs 11days; p=0,007, respectively). Intensive care costs were also significantly higher in the frail group (1540 vs 1242 US Dollar; p=0,019). The total mortality rate was 39.9%; in frail group. This rate was significantly higher than non-frail group (48,6% vs 29,3%; p<0,0001). Frailty (CFS≥5) were shown to be an independent risk factor for mortality (p=0.014, OR 1.464, 95% CI 1.081-1.982)Conclusion: We recommend the routine use of CFS, which is especially useful in predicting frailty and mortality in intensive care unit.