Alcohol misuse and alcohol withdrawal are associated with a variety of neuropsychiatric syndromes, some of which are associated with significant morbidity and mortality. B vitamin deficiency is known to contribute to the aetiology of a number of these syndromes, and B vitamin supplementation thus plays a significant part in prophylaxis and treatment. In particular, the Wernicke Korsakoff syndrome (WKS). due to thiamine deficiency, is a common condition in association with alcohol misuse, and is associated with high morbidity and mortality. Nicotinamide deficiency may result in a rarer condition, alcoholic pellagra encephalopathy, which often has a similar clinical presentation to WKS. This review considers the role of B vitamins in the aetiology and treatment of neuropsychiatric syndromes associated with alcohol misuse, with particular emphasis on WKS.