In several clinical trials, mainly conducted with a dose of 300 mg kava extract per day, kava has been employed successfully for the treatment of anxiety disorders. The goal of the placebo-controlled double-blind outpatient trial was to obtain more information on the dosage range and efficacy of a kava special extract WS 1490 in patients with non-psychotic anxiety. 50 patients were treated with a daily dose of 3 x 50 mg WS 1490 during a 4-week treatment period followed by a 2-week safety observation phase. In the active treatment group, the total score of the Hamilton anxiety scale (primary efficacy variable), showed a therapeutically relevant reduction in anxiety versus placebo (more than 4 points). In the secondary variables studied, HAMA 'somatic and psychic anxiety' subscales, the Erlangen anxiety, tension and aggression scale (EAAS), the brief personality structure scale (KEPS), the adjective checklist (EWL 60-S) and clinical global impressions scale (CGI), a trend in favour of the active treatment was detectable. WS 1490 was well tolerated and showed a safety profile with no drug-related adverse events or post-study withdrawal symptoms. It can be concluded that the applied 150 mg WS 1490 per day is an effective and safe treatment of non-psychotic anxiety syndromes in the described population.