Motivation plays an important part in an elderly individual's ability to recover from a disabling event. On the other hand, apathy is a lack of motivation. The Apathy Evaluation Scale (AES) is an 18-item instrument that rates a person's thoughts, actions, and emotions over the previous 4 weeks. The purpose of this study was to use the AES with 102 patients in a geriatric rehabilitation program to determine if it predicted improved function after rehabilitation. In addition, a short 7-item version of the AES was tested. A strong correlation was demonstrated between the 18-item AES and the 7-item AES, the Mini-Mental State Examination, and the Geriatric Depression Scale. In separate regression analyses, we found that admission function and both the 18-item and 7-item AES were significant predictors of discharge function, and that functional level at admission to rehabilitation accounted for 31% of the variance in function after rehabilitation. The findings suggest that the AES might be an appropriate measure of motivation in older adults and might predict success in rehabilitation. Moreover, the ability to identify patients with low motivation can alert healthcare providers to develop interventions to improve older adults' motivation and help them attain and maintain their highest functional level.