To investigate the relationships between gastric change accompanying patients with acute stroke and the function of the autonomic nervous system and pituitary-adrenal system, studies on the gastroendoscopic technique and biochemical observations were done in 122 patients. The mean urinary noradrenalin and adrenalin excretions were elevated in patients with acute gastric changes, especially in patients with multiple erosions and acute ulcers. An elevation of the mean fasting serum gastrin concentration was found in patients with acute ulcers and no acute gastric changes. The mean urinary 17-OHCS excretion was increased in patients with multiple erosions, petechiae and acute ulcers. In conclusion, the sympathetic and parasympathetic nervous system and the pituitary-adrenal system have respectively different roles in the production of various types of acute gastric changes in patients.