Unresolved questions about the inverse relation between alcohol consumption and coronary artery disease (CAD) include; Dose past drinking have a role in the apparently higher CAD risk of abstainers? Is the lower CAD risk found only among lighter drinkers? Does type of alcoholic beverage matter? Are abstainers at higher risk of CAD because symptoms or illness cause many to quit drinking? In a prospective study among 85,001 health examinees giving an alcohol history at a health examination from 1978 through 1982, 756 persons were later hospitalized for CAD in the same years. Using lifelong abstainers as the reference group and controlling for age, sex, race, smoking, coffee drinking and education, analysis showed that past drinkers and very infrequent drinkers had CAD risk similar to that of lifelong abstainers. A significantly and progressively lower CAD risk was found at higher drinking levels. Preference for wine, liquor or beer had no major independent effect. A subset of persons apparently free of CAD and other recent major illnesses showed a similar alcohol-CAD relation. Thus, this study suggests a negative answer to the 4 questions above and supports the view that alcohol protects against CAD. As most of the apparent protection was present at a daily intake of 1 to 2 drinks/day, an amount generally regarded as safe for most persons, the findings should not be used to justify heavier drinking.