The purpose of this study was to describe changes that occur in mental status in older adults during 4 days of hospitalization in an acute-care setting. It was hypothesized that elderly patients would experience significant changes in all components of mental status (i.e., level of consciousness, orientation, attention/concentration, memory, higher cognitive functions) during this period of time. A sample of 25 individuals ranging in age from 65 to 89 years was obtained from the medical and surgical units of an acute-care hospital. Each individual's mental status was evaluated twice using a mental status examination designed for the study. The first assessment was conducted on the afternoon of admission day, and the second was completed on the fourth hospital day. Statistically significant changes in three components of mental status were found: disorientation increased, level of consciousness declined, and memory improved. The significance of these findings for nursing is discussed.