Two dimensions are identifiable in nursing hospital caring: a) nurse activities based on nurse critical evaluation, carried-out in order to achieve patients highest independence; b) nurses activities implementing routinely care and medical prescriptions. Therefore, in order to improve the appropriateness of their evaluations, nurses should measure patients level of dependence using valid and reliable instruments. The study was designed to develop and test a dependency scale for hospitalized patients, in order to better identify their needs of nursing care; the study was carried out at Udine University Hospital. The instrument developed (ADI 8) is a eight-ranks scale. A comparative validation between ADI 8, Barthel Index ans Swiss Grid (MS) proved that ADI 8 has more discriminative power for medium dependency level subjects. Moreover, ADI 8 showed less tendency to overestimate than Bartel Index. Reliability test was carried out using paired observers in blind mode. Kendall statistics proved that ADI 8 possess high reliability for each factor and overall (.80).