BACKGROUND: Critically ill patients are at high risk for pressure ulcers. OBJECTIVES: To determine the contributions of the Braden subscales in predicting pressure ulcers in critically ill patients and to investigate how often the Braden scale should be completed to assess the risk for pressure ulcers in critically ill patients. METHOD: The Braden scale was used to assess repeatedly 136 adult patients without pressure ulcers in a medical intensive care unit, a surgical intensive care unit, and a noninvasive respiratory care unit, and the patients' skin was inspected routinely for pressure ulcers. RESULTS: A total of 36 pressure ulcers, most commonly on the sacrum or coccyx and the heels (15 stage 1, 20 stage 2, 1 stage 3), developed in 17 patients (12%). In 14 (82%) of the 17, the ulcers developed within 72 hours of admission to the intensive care unit. The risk for pressure ulcers increased as the mean sensory perception (P = .01) and the mean total Braden (P = .046) scores decreased. The mean sensory perception scores obtained at 12 and 36 hours after admission also had a significant relationship to the risk for pressure ulcers (P = .03). CONCLUSIONS: Patients in intensive care units have an increased risk for pressure ulcers. Although waiting until 12 hours after a patient's admission to the intensive care unit to obtain the initial Braden rating may be reasonable (with the second rating obtained 36 hours after admission), additional research is needed before this practice can be recommended.