The results of health examinations of 89,299 examines from companies in Fukui Prefecture conducted pursuant to the Occupational Safety and Health Act were analyzed to study the relationship between the prevalence in these companies of hypertension, and company size business type. The Mantel-Haenszel method was utilized to adjust for age structure of the examinees according to gender and the type of business of their companies to compare prevalence of hypertension. The results of the analysis indicated that the prevalence of hypertension was significantly higher in small-scale companies for the female examinees working in pulp/paper processing and motor freight transport business than in large-scale companies, but no significant difference was seen for scale of business when the female examinees were grouped without regard to the business type of their companies. In the case of the male examinees, the analysis results revealed that the prevalence of hypertension was significantly higher in small-scale companies for those working in ceramic/earth/rock, motor passenger transport and hotel/restaurant business than in large-scale industry while the prevalence of hypertension was significantly higher in large-scale companies for those working in non-ferrous metal industry, financial and other types of business. Moreover, the analysis results for the male examinees grouped without regard to the type of business of their companies indicated that the prevalence of hypertension remained significantly higher in small-scale companies. The above also suggests the need for measures for health care of workers that considers business type and scale for the purpose of primary prevention of hypertension.