We compared the costs of acamprosate in maintaining abstinence in weaned alcoholic patients, to no pharmaceutical treatment over a 24-month period. A controlled trial (n=448) involving a 12-month treatment with acamprosate and a 12-month follow-up showed a significant advantage of acamprosate over placebo in the prevention of relapse. For the economic analysis, the average costs of relapses from the health insurance perspective were calculated based on a Belgian survey among general practitioners and on an observational prospective Belgian trial among specialists. Calculations resulted in net cost savings of 21,301 BEF (528 Euro) per patient over a 24-month period for acamprosate compared to no pharmaceutical treatment, explained by fewer acute hospitalisations for detoxification and less institutionalised rehabilitation. A global anticipated net saving of 70 million BEF (1.74 million Euro) over 2 years was estimated for the Belgian health insurance. Copyright 2000 S. Karger AG, Basel.