Abstract Background: Several studies have identified certain caregiver factors that can produce variability in their assessments of the capacities of patients with Alzheimer"s disease (AD). Objectives: To identify the caregiver variables associated with variability in their ratings of patients" capacities. Methods: Consecutive sample of 221 out-patients with AD and their family caregivers. The capacities evaluated by caregivers were: the degree of functional disability, using the Disability Assessment for Dementia (DAD); psychological and behavioral symptoms, via the Neuropsychiatric Inventory (NPI); anosognosia, with the Anosognosia Questionnaire Dementia (AQ-D); and quality of life, using the Quality of Life in AD (QOL-AD). The relationship between these measures and caregiver gender, burden, depression, and health was analyzed by means of a bivariate analysis, calculating the effect size (Cohen"s d), and subsequently by a regression analysis, calculating the contribution coefficient (CC). Results: The greatest variability in caregiver assessments was observed in relation to patients with early-stage dementia, where caregiver burden was the main factor associated with a more negative evaluation (d = 1.02 to 1.25). Depression in the caregiver was associated with less variability and only in the assessments of patients with moderate dementia (d = 0.38 to 0.69). In the regression analysis, caregiver factors were associated with greater variance in scores on the NPI (CC = 37.4%) and QOL-AD (CC = 27.2%), and lower variance in AQ-D (CC = 21.6%) and DAD (CC = 10.3%) scores. Conclusions: Caregiver burden and depression were associated with more negative assessments of patients" psychological and behavioral symptoms and quality of life. Key words: Alzheimer"s disease, family caregivers, functional capacity, neuropsychiatric symptoms, anosognosia, quality of life.