Hypertensive tendencies in the rural inhabitants of north-east Japan are discussed in relation to data collected on the Pacific side of that area. Effects of environmental conditions on blood pressure level are considered under 3 headings; physical environment, diet and socioeconomic circumstances. It is reasonably certain that pressure is inversely related to temperature, but the effect of noise at place of work appears to be unimportant although it can cause a physiological rise. With regard to diet, the consumption of a large amount of polished rice with few vegetables but much salt seems to be a factor increasing the prevalence of hypertension and cerebral hemorrhage in these districts. The effects of socioeconomic circumstances is less clear, perhaps because the extent of socioeconomic variation is limited in these rural districts. Further investigation of the factors influencing the hypertensive tendency in these areas is needed.