Although cigarette smoking produces an acute rise in blood pressure (BP), results from epidemiologic studies have generally shown smokers to have lower BP than nonsmokers. This phenomenon has frequently been ascribed to a failure to account for other BP-associated differences between smokers and nonsmokers. Consequently, the role of cigarette smoking as a risk factor for hypertension remains unclear. In this article the results of a large epidemiologic study of smoking and BP in a working population are presented. The results show a pattern of higher BP among nonsmokers and ex-smokers than among smokers. These differences could not be explained by various potentially confounding factors, such as relative weight, ethnic origin, alcohol and coffee intake, and participation in leisure time sports. While the considerable adverse effects of smoking on health are well established, the role of smoking as a risk factor for hypertension is not supported by the epidemiologic evidence. Furthermore, the data are highly suggestive of lower BP among smokers compared with nonsmokers, whereas ex-smokers have BPs similar to those of nonsmokers.