Objective: To determine whether orthostatic hypotension (OHYPO) and visit-to-visit blood pressure (BP) postural changes variability are associated with incident dementia. Methods: We studied 2,131 older adults from the Health, Aging, Body Composition cohort study. Orthostatic BP was repeatedly assessed over a 5-year baseline period. OHYPO was defined as a fall ≥ 15 mmHg in systolic or ≥ 7 mmHg in diastolic BP after standing from a sitting position for ≥ 1/3 of visits. Systolic and diastolic OHYPO were also examined separately. BP postural changes variability over time was evaluated using several indicators including standard deviation and coefficient of variation (CV). Incident dementia was determined over 12 years following the baseline period by dementia medication use, ≥ 1.5 SD decline in Modified Mini-Mental State or hospitalization records. Results: Of 2,131 participants (mean age 73 years, 53% female, 39% black), 309 (14.5%) had OHYPO, 192 (9.0%) systolic OHYPO, 132 (6.2%) diastolic OHYPO and 462 (21.7%) developed dementia. After adjustment for demographics, seated systolic BP (SBP), antihypertensive drugs, cerebrovascular disease, diabetes, depressive symptoms, smoking, alcohol, body mass index and presence of 1 or 2 APOE ε4 alleles, systolic OHYPO was associated with greater dementia risk (adjusted HR = 1.37, 95% CI 1.01-1.88) unlike diastolic OHYPO and OHYPO. SBP postural changes variability was also associated with higher dementia risk (highest tertile of variability (CV): adjusted HR = 1.35, 95% CI 1.06-1.71). Conclusion: Systolic OHYPO and visit-to-visit SBP postural changes variability were associated with greater dementia risk. Our findings raise the question of potential preventive interventions to control orthostatic SBP and its fluctuations.