With the Framingham Heart Study widely recognized as the most comprehensive, sustained investigation of the precursors of coronary heart disease (CHD), an examination was made of its manifold published data on the relationship of cigarette smoking to CHD and the results were compared with the "conventional wisdom" about cigarette smoking and CHD as projected by the Surgeon General. The analysis of data in the Framingham Heart Study shows that its results are inconsistent with the Surgeon General's views about cigarette smoking and coronary heart disease. The inconsistencies refer to (1) the magnitude of the association between cigarette smoking and CHD; (2) the relative incidence of CHD in "heavy" smokers and nonsmokers; (3) the independent effect of cigarette smoking on CHD; (4) the increasing risk of developing CHD with duration of cigarette smoking; (5) the effect of smoking cessation; and (6) the association between cigarette smoking and CHD in women.