Background: To investigate the association between diuretics, angiotensin-converting enzyme inhibitors (ACE-I), angiotensin II receptor blockers (AT2RB), and cognitive function. Methods: This post hoc analysis of the randomized controlled Ginkgo Evaluation of Memory Study trial focuses on 3069 nondemented community-dwelling participants aged >75 years. At baseline visit, detailed information about medication use was collected and five cognitive domains were assessed. Multivariate linear regression analyses were used to assess cross-sectional associations between medication use and cognitive function. Results: In all, 36% of participants reported history of hypertension and 53% reported antihypertensive medication use, with 17% reporting diuretic, 11% ACE-I, and 2% AT2RB use. Potassium-sparing diuretic use (N = 192) was associated with better verbal learning and memory measured by California Verbal Learning Test as compared with no antihypertensive medication users (β = 0.068, P =.01; β = 0.094, P <.001) and other antihypertensive medication users (β = 0.080, P =.03; β = 0.153, P <.001). Use of ACE-I or AT2RB was not associated with better cognitive function. Conclusion: Results warrant further investigation into possible protective effects of potassium-sparing diuretics and the role of potassium in mitigating cognitive decline. © 2012 The Alzheimer's Association. All rights reserved.