Nursing Practice Models (NPMs) represent the structural and contextual features that exist within any group practice of nursing. Currently, measurement of NPMs relies on costly and nonreproducible global judgments by experts. Quantitative measurement techniques are needed to provide a useful evaluation of nursing practice. Guided by Multi-Attribute Utility theory (MAU theory), an expert panel identified 24 factors representative of NPMs. The factors became elements in a computational index that, when summed, assigns a score to a given nursing unit reflecting the extent to which that unit’s nursing practice model achieves the nursing professional ideal. Initial validation of the index and its elements consisted of comparing assessments of 40 nursing units generated by the index with a global evaluation provided by each of the expert panelists who proposed the model factors. Pearson correlations between the index-generated scores and the global assigned scores provided evidence supporting the preliminary validation of the index. © 2000 John Wiley & Sons, Inc. Res Nurs Health 23:372–382, 2000.