Background: Pressure ulcers are localized damage in the bedridden patient`s skin that increase morbidity and mortality rates and it can be prevented if appropriate nursing measures are implemented. Aim: The present study was aimed to determine relationship between nurses` knowledge,practice and their Perceived barriers toward PU prevention. Research design: a descriptive correlational design was utilized for the current study. Sitting:The study was conducted in the orthopedic, neurosurgery and intensive care units at El-Mahalla General Hospital and Benha University Hospital. Sample: A convenient sample of all available nurses (40 nurses from each hospital) were included in the study and eighty patients (40 patients in each hospitals) who are assigned for care by studied nurses who participated in the study. Two tools were employed in this study, Tool 1:It included 2 parts, part I:concerned with Nurses` knowledge assessment and sociodemographic characteristics, Part II: attributed to perceived barriers towards pressure ulcer prevention practice. Tool 2: It included 2 parts, Part I: included nurses' practice observational checklist toward actual nurses' care for pressure ulcer prevention.Part II: Patients` diagnosis and their functional level observational checklist. Result and conclusion: The present study revealed that nurses' knowledge was satisfied while their practice was unsatisfied which it may be attribute to that they did not integrate their knowledge into practices. There was statistically significant correlation between level of nurses’ knowledge and practice in Benha and El Mahallaand between nurses’ practice and perceived barriers by nurses in El Mahalla hospital.Recommendations:The present study recommended that continues education and in service training program for the nurses, which is necessary for improving care provided for patients. Health service managers should identify and minimize the barriers as much as possible to prevent pressure ulcer.