Clinical guidelines for cholesterol testing and management have been updated recently. With the evolving recognition of benefits and intensified recommendations for cholesterol management, many more patients will require cholesterol-lowering drugs. All the statins share similar adverse-effect profiles, with a low overall frequency of undesirable effects. Emerging data associate statins with a decreased risk of Alzheimer's disease; however, we report two women who experienced significant cognitive impairment temporally related to statin therapy. One woman took atorvastatin, and the other first took atorvastatin, then was rechallenged with simvastatin. Clinicians should be aware of cognitive impairment and dementia as potential adverse effects associated with statin therapy.