Introduction: pressure lesions are localized damage in skin and/or underlying soft tissue, usually over a bony prominence or related to a medical device or other device. In Intensive Care Units patients are critically susceptible to the development of lesions by pressure, for various reasons.Objective: to identify predisposing conditions and risk factors of pressure ulcers in patients admitted to an Intensive Care Unit of a mid-sized general hospital in the Western region of the State of Rio Grande do Norte (RN), Brazil.Method: nonparticipating observational study with documentary stage, of prospective longitudinal type, performed in ICU of adult kind of a General Hospital in the city of Mossoro-RN, Brazil. Data collection took place on alternate days during 43 days between May and June 2012. The research protocol was approved by the CEP/UERN under opinion No. 67606/12.Results: the intrinsic risk factors for the emergence of the most evident pressure injuries were decreased pain sensitivity, reduced turgor and elasticity, evidenced bony prominences and impaired physical mobility. Extrinsic risk factors were the pressure force on the body and forces of friction and shear. The chronic obstructive pulmonary disease, impaired motor skills and evidenced bony prominences, specifically in the sacral region, were statistically significant factors in association with the development of pressure injuries.Conclusions: to provide a comprehensive and qualified assistance, it is necessary to invest in improvement of the assistance provided through the adoption of appropriate measures for customer care, education and multidisciplinary team training, as well as the participation of the institution with the promotion of appropriate work conditions for the multidisciplinary team, promoting qualified assistance to the patient.