The purpose of this study was to test the discriminant validity and interrater reliability of an instrument that measures aspects of self-care agency using Norwegian populations. The ASA scale forms A and B, which had been tested in the Netherlands previously, were translated into Norwegian and administered to two groups of elderly subjects and to a sample of geriatric nurses and nursing assistants in Norway. The subjects, one group from two geriatric rehabilitation units, and another from those living independently who were attending activity centres, completed the ASA-A scale. The nurses filled out the ASA-B scale. The results were supportive of the validity and reliability. Discriminant validity of the ASA scales was demonstrated.