In 2004, the United States Food and Drug Administration (FDA) approved acamprosate for use in conjunction with psychosocial support in the maintenance of abstinence in alcohol-dependent patients who are abstinent at treatment initiation. That approval was based primarily on a re-analysis of three European double-blind, placebo-controlled trials in which complete abstinence was the primary outcome measure. The current report presents data from the re-analysis of the pivotal trials, which were 13-, 48-, and 52-week studies. A total of 998 DSM-III-R alcohol-dependent patients were included in the studies, with the majority abstinent at randomization. Using a more stringent definition of abstinence, re-analysis of the rate of complete abstinence, percent days abstinent, and the time to first drink confirmed the original findings for the efficacy of acamprosate in the treatment of alcohol dependence. Rate of complete abstinence was significantly higher with acamprosate than placebo (p < .05); both percent days abstinent and time to first drink were also significantly greater among acamprosate-treated than placebo-treated patients (p < .01). These findings support the use of acamprosate in the treatment of alcohol dependence and illustrate some of the issues that can arise in the FDA process for approval of medications to treat the disorder.