Behavioral disturbances in Alzheimer's (AD) patients might be caused by environmental factors. The authors tested the hypothesis that delusions in AD might be a result of caregiver's distress. Participants were 22 delusional and 21 nondelusional mild AD patients and their caregivers. Those who cared for nondelusional patients, compared with the delusional patients' caregivers, reported higher levels of distress because of behavioral disturbances other than delusions. When patients were stratified into 2 groups according to median distress value, 64% of the delusional patients and 33% of the nondelusional patients showed a high level of caregiver's distress, chi2(1, N = 43) = 3.94, p = .047. Although final conclusions about the causal direction of the association cannot be drawn, these findings are consistent with the hypothesis that distressed caregivers might use inappropriate coping strategies that, in turn, might favor the development of delusions.