Sho-hange-ka-bukuryo-to and Nichin-to, traditional Chinese herbal (Kampo) medicines have been used to treat vomiting and nausea. Traditional herbal medicines have frequently been used in the empirical treatment. Some patients who take these medicines have no organic disease but have conditions classified as non-ulcer dyspepsia (NUD). To determine the pharmacological effects of Sho-hange-ka-bukuryo-to, Nichin-to, and the two herbs (Pinelliae Tuber and Zingiberis Rhizoma, both of which are included in Sho-hange-ka-bukuryo-to and Nichin-to), we examined the effects of these medicines on the plasma levels of adrencorticotropic hormone (ACTH) and cortisol under stress conditions by repetitive blood sampling. After a single administration of Kampo medicine or a placebo, venous blood samples were taken before and 20—240 min after administration. A single administration of Sho-hange-ka-bukuryo-to caused significant suppression of an increase in plasma ACTH-immunoreactive substance (IS) levels at 120 to 180 min and tended to suppress increases in plasma cortisol levels at 240 min, compared with the response to a placebo. A single administration of Nichin-to caused significant suppression of increases in plasma ACTH-IS levels at 120 min compared with a placebo group, but had no effect on plasma cortisol levels. Pinelliae Tuber had no significant effects in plasma ACTH-IS or cortisol, but Zingiberis Rhizoma significantly suppressed the increase of ACTH-IS (120 min) and cortisol (180 min). These medicines have a modulatory effect on the hypothalamo-pituitary-adrenal (HPA) axis and autonomic nervous function. These effects might be beneficial in stress-related disease and suggest that this medicine has clinical pharmacological activity.