Brief and uncomplicated methods for obtaining information on functional status would facilitate the assessment of older patients. We evaluated the potential usefulness, reliability, and validity of four hierarchical measures of physical function in 123 elderly subjects seen in four ambulatory geriatrics settings. Although the vast majority (83.2%) of subjects were fully independent on the Katz Activities of Daily Living Scale, a broader scope of functional difficulty was reported on the Spector-Katz, five-item OARS, and Rosow-Breslau scales. The three scales all had either borderline or more acceptable coefficients of scalability (0.57-0.77); the hierarchical order of items was not observed in 5.3% to 13.6% of subjects. Combining items from these established measures resulted in two new scales with acceptable scalability and construct validity; however, some errors in item order persisted. Although their ease of administration is clearly advantageous, clinicians using short hierarchical scales to assess functional status of older patients should be aware of their limitations.