This talk will cover current knowledge of the mechanisms of action of pharmacological treatments for alcohol dependence, with a particular focus on the prevention of relapse drinking during abstinence. There will first be a brief discussion of the neuronal basis of the alcohol withdrawal syndrome and the mechanisms of action of pharmacological treatments for this syndrome. Information on the basis of the reinforcing and rewarding effects of alcohol, and their importance in the development of alcohol dependence will then be presented. Our current knowledge of the changes that take place in central nervous system function during chronic excess alcohol consumption, and how these might affect behaviour, will be described. Two relatively new developments in treatment of relapse drinking, naltrexone and acamprosate, will then be discussed, with information about common knowledge, or lack of knowledge, of their mechanisms of action. Potential pharmacological candidates that may provide new approaches to the treatment of dependence in the future will be described. The presentation will also cover the advantages and limitation of the models used for the development of pharmacological treatments for alcohol dependence.