The aim of this study was to evaluate visit-to-visit blood pressure (BP) variability in a cohort of patients with Alzheimer disease (AD) and healthy controls. Patients with clinically diagnosed mild or moderate AD and cognitively normal controls matched for age and sex were recruited and followed up for 6 months. To characterize the BP status of each individual, mean, maximum and minimum values, SD, and coefficient of variation were obtained for both systolic BP (SBP) and diastolic BP (DBP). Seventy AD patients and 140 controls were enrolled. No meaningful differences were found in prevalence or treatments of various vascular risk factors. AD patients had higher maximum and lower minimum values and greater SD and coefficient of variation of both SBP and DBP. Group differences in mean values were significant only for SBP. In the multiple logistic regression analysis, adjusted for confounding variables, all the indices related to BP variability were significantly associated with AD. Our results show that AD patients have a greater variability of both SBP and DBP in comparison with age-matched cognitive normal controls, suggesting potential implication in the pathogenesis or progression of the disease.