At the time of hospitalization for a heart attack, about one third of the patients were nonsmokers, one third were former smokers, and one third were active smokers. Of the active smokers, 39% had quit during hospitalization and 61% continued to smoke. After hospitalization, 272 nonfatal heart attacks, 94 fatal heart attacks, and 67 other heart-related deaths occurred. Compared to nonsmokers, the risk for a bad cardiac outcome was 1.43 times as high among quitters and 1.51 times as high among active smokers. Former smokers had the same risk as nonsmokers. Among those who quit smoking after their heart attack, the risk gradually fell to about the level of the nonsmoker after 36 months.