Background: Understanding caregiver's perceptions of their family member's memory loss is a necessary step in planning nursing interventions to detect and address caregiver burden. Objective: The purpose of this study was to characterize caregivers' perceptions of their family members' memory loss and identify potential correlates within Leventhal's common sense model (CSM). Methods: This secondary analysis used baseline data from a larger randomized controlled trial. Patients with memory loss and their caregivers (N = 83 dyads) from the community were included, The adapted Brief Illness Perception Questionnaire (BIPQ) assessed caregivers' illness perceptions. Eight additional instruments measured correlates within the CSM. Responses were described; multiple linear regression was used to predict BIPQ dimension scores, and logistic regression was used to predict dichotomized BIPQ scores. Results: Most caregivers were female, White, and spouses of the patients; they reported a range of perceptions on the nine BIPQ dimensions. Patients' cognitive function consistently emerged as a significant correlate of caregivers' illness perceptions, explaining the most variance in caregivers' perceived consequences, identity, and treatment control (p < .01). Caregivers' reactions to patients' behavioral symptoms and caregivers' trait anxiety were associated with perceived illness coherence (p < .01), Caregivers with higher severity of daily hassles and White caregivers perceived that their family members' memory loss would last longer (p < .001). Discussion: Caregivers' perceptions of family members' memory loss varied; distinct dimensions of caregivers' illness perception were associated with a range of clinical and psychosocial factors. This exploratory study demonstrates the complexity of applying the CSM to caregivers of persons with memory loss.