Aim. This study aimed to examine the effect of application of Braden PRESSURE ULCERS risk assessment tool on performance of critical care nurses.Background. PRESSURE ulcer is a common phenomenon in patients admitted to intensive care unit. The MANAGEMENT of PRESSURE ULCERS in these patients is a challenging task. Therefore, PRESSURE ulcer prediction tools are used when dealing with these patients.Method. This quasi-experimental study was conducted in the intensive care units. The study sample consisted 68 critical care nurses working inintensive care units of selected hospitals of Tehran University of Medical Sciences in 2013. After determining the sample size and obtaining permission from theethics committee of Tehran University of Medical Sciences, the participants were recruited through convenience sampling based on inclusion criteria. Critical care nurses of two intensive care units of general hospitals of Tehran University of Medical Sciences were selected as experimental and control group. In both groups, after collecting demographic characteristics, their performance in the MANAGEMENT of patients who were at risk for PRESSURE ULCERS was evaluated by the checklist whose validity and reliability was evaluated by the faculty members of Tehran University of Medical Sciences. The data were analyzed by descriptive and inferential statistics in SPSS version 19.Findings. There was no statistically significant difference between the groups in terms of demographic characteristics. After the intervention, the mean score of nurses performance in the experimental group was 66.21±0.47 and that of control group was 62.59±1.31 (p≤0.0001). After intervention, all nurses in the experimental group had very good performance and nurses in the control group had good performance.Conclusion. Using the PRESSURE ULCERS risk assessment tool (Braden scale) increases the sensitivity of critical care nurses to the risk of ulceration in the intensive care unit patients and forces them to comply with the standard caring measures and consequently, lead to prevention of bed sores. It is recommended to use this tool in order to enhance the care MANAGEMENT of patients prone to PRESSURE sore.