In this longitudinal study, we investigated the effects of institutionalization on the sense-of-self in individuals with Alzheimer's Disease (AD). We recruited two groups of participants: one living in care facilities (i.e., institutionalized-group) and another group living in their own home (i.e., non-institutionalized-group). In the two groups, we assessed the "Who-am-I" task on which participants were invited to provide statements beginning with the phrase "I am" that they felt were essential in defining who they are. We assessed this task, in the two groups, at a baseline (approximately one-month before-institutionalization) and at a follow-up (approximately six months after institutionalization). We analyzed whether responses on the "Who-am-I" task reflected physical-, social-, or psychological-self. Unlike at the baseline, fewer statements describing physical-, social-, and psychological-self were observed in the institutionalization than in the non-institutionalized group at the follow up. These findings demonstrate negative effects of institutionalization on the sense of self in AD.