Cranial electrotherapy stimulation (CES) is reported to be an effective treatment for anxiety, a major presenting symptom among chemically dependent patients. In this study, 40 inpatient alcohol and/or polydrug users were given CES or sham CES in a double blind design. An additional 20 patients served as normal hospital routine controls. Dependent measures of anxiety were the Profile of Mood States, the Institute for Personality and Ability Testing Anxiety Scale, and the State/Trait Anxiety Index. CES-treated patients showed significantly greater improvement on all anxiety measures than did either control group. There were no differences in response between older and younger patients, or between the primarily drug or alcohol abusers. No placebo effect was found on any of our measures. It is concluded tht CES is a clinically significant addition to the treatment regimen for this patient population.