The purpose of the present paper was to investigate the efficacy of kamishoyosan (TJ-24), a traditional Japanese herbal formula (kampo), for outpatients with premenstrual dysphoric disorder (PMDD) as an alternative treatment. Thirty patients with PMDD were treated with TJ-24 for six menstrual cycles. Nineteen patients (63.3%) had >50% improvement in the total score of the Hamilton Depression Rating Scale (HAM-D) Scale (17 items) in the late luteal phase. Fourteen patients (46.7%) went into remission (total HAM-D score <7). In the present study many patients with PMDD were successfully treated with TJ-24.