Background: Pressure ulcer is localized tissue necrosis that commonly develops on a bony prominence areas when soft tissue compressed for prolonged period of time. Critically ill patients are considered to be at greatest risk for pressure ulcer development. So that, nurses are the first line health professionals to provide adequate care. Objectives: To assess knowledge and practice of Adult Intensive care Unit nurses and their barriers towards pressure ulcer prevention and management in selected public Hospital, Addis Ababa, Ethiopia 2017. Methods: A descriptive cross-sectional survey was carried out among (N=128) Adult Intensive care Unit nurses in six selected public Hospitals. Simple random Sampling techniques was used to select sample hospitals in order to find research participants. In addition standardized questionnaire was used to collect data. Result: The study findings showed that the level of nurses’ knowledge regarding pressure ulcer prevention and management was good (Mean=18.52, SD+2.686), while the level of nurses’ practice was poor (Mean=12.39, SD+4.70924).Shortage of pressure relieving devices, inadequate training and education and presence of other priorities other than pressure ulcers were majorly cited barriers to carry out PrU care efficiently. The nurses’ knowledge has association (AOR= 2.499, p value = 0.028) with training but not with their practice and barriers. In addition nurses’ practice has significant association with barriers. Conclusions: In general, the study results indicates that nurses have good knowledge of PrU prevention and management but accounts poor practice. As a result the study recommends for the provision of in service training and fulfillment of proper equipments for AICU nurses and unit. The study finding implies the need for further researches and it will be used as point of reference. Keywords: Pressure ulcer, Knowledge, Practice, Barriers