This study examines the empirical basis for dividing activities of daily living (ADLs) into broad behavioral domains. Following an exploratory factor analysis of results from the Cleveland Scale for Activities of Daily Living (CSADL), a two-factor model of ADLs was tested in a confirmatory factor analysis using two groups of demented patients. The model, which included a Basic and an Instrumental factor, was confirmed. Comparison of the item composition of the CSADL factors with a priori domains used by other ADL scales suggested that the results of the present study are broadly generalizable. The two factors are correlated, and cautions were raised concerning the likelihood that many ADL items may reflect both basic and instrumental domains.