Acamprosate is a relatively new drug that appears to be clinically useful in the treatment of alcohol dependence. Although it has proved effective in reducing relapse into drinking in clinical trials its exact mechanism of action is uncertain. Evidence is presented that the drug does not act in any of the conventional ways to reduce alcohol intake and it is proposed that it may be a novel kind of agent that suppresses "craving". On the basis of its known pharmacological effects in pre-clinical studies it is suggested that acamprosate may reduce craving that is associated with conditioned withdrawal. In addition to the potential therapeutic value of acamprosate, the drug may be useful because work directed toward understanding its mechanism of action may shed light on some of the fundamental processes that govern alcohol abuse and relapse in weaned alcohol dependent patients.