The objective of this article was to determine the most suitable cutoff point (CP) for the Braden Scale and Norton Modified Scale by INSALUD Scale (Norton-MI) in an acute care hospital.The authors have designed a prospective, descriptive study of patients from their hospital. From December 2008 to March 2009, a nurse collected and recorded adult patient data daily, including the appearance of pressure ulcers.Adult patients in medical and surgical wards.The parameters used in both scales are sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), area under curve (AUC) of receiver operating characteristic (ROC).In the end, the authors have evaluated a total of 1001 patients and obtained 4486 measurements with both the Norton-MI and the Braden scales. The rates for the recommended CP of the Norton-MI scale (CP 14) are as follows: sensitivity: 67.91% (62.42-73.39), specificity: 78.66% (77.41-79.92), PPV: 18.36%, NPV: 97.20%. Those for Braden (CP 16) are as follows: sensitivity: 65.69% (64.19-75), specificity: 79.62% (78.39-80.85), PPV: 19.43%, NPV: 97.37%. The Norton-MI scale offers an AUC-ROC of 0.828 with a 95% confidence interval of 0.811-0.854, and the Braden Scale presents an AUC-ROC of 0.832 with a 95% confidence interval of 0.807 to 0.849.Both scales show good validity data. If the CP is raised: MI-Norton (CP 15): sensitivity: 77.36 (72.43-82.30), specificity 74.27 (72.94-75.61), PPV: 17.52 (15.42-19.62), NPV: 97.89 (97.38-98.41). The Braden scale with a CP of 17 presents sensitivity: 78.38 (73.52-83.24), specificity: 73.44 (72.09-74.79), PPV: 17.25 (15.19-19.31), NPV: 97.96 (97.45-98.47). These CPs improved the predictive capacity of both scales in the authors' hospital environment.