Adverse effects of alcohol on the peripheral and central nervous system can be direct (ie, neurotoxicity) or indirect (eg, nutritional deficiency). Using the case of Mr E, an older, moderate to heavy drinker experiencing memory difficulty, the diagnostic considerations, which include mild cognitive impairment, early Alzheimer dementia, Wernicke-Korsakoff syndrome, and “alcoholic dementia,” are discussed. These disorders are not mutually exclusive, and in a patient with either mild cognitive impairment or dementia, the contributory role of alcohol can be difficult to determine. In fact, epidemiological studies suggest that mild to moderate intake of alcohol actually reduces the risk of developing mild cognitive impairment or dementia, including Alzheimer dementia. Appropriate management includes measures to reduce alcohol dependence (eg, behavioral or pharmacological therapy) and to delay progression of the cognitive impairment (eg, engaging in healthy behaviors such as cognitive leisure activities).