The validity of pressure ulcers risk assessment scales remains a topic of considerable debate and uncertainty. The aim of this study was to compare the predictive validity of Waterlow vs Norton scale in elderly patients hospitalized in an Internal Medicine Dpt. The pressure ulcer risk was scored on admission in 72 patients aged 81 ±8 years old by using the questionnaires of both scales. The patients were assessed daily until a new pressure ulcer grade II occurred (22 patients). The sensitivity and specificity of Waterlow scale (score >20) and Norton scale (score < 8) were 96% vs 94% and 75% vs 81% respectively. It is concluded that both scales were reliable and comparable provided that an appropriate cut off point was used.