To determine how denial of illness affects the relationship between self-reported psychological state and cardiac status, the authors studied 204 men with heart disease. Differing degrees of denial masked the relationship between multiple-vessel coronary disease and tension, depression, or fatigue. At 1-year follow-up, denial confused the relationship between fatigue and cardiac state. Denial may augment or diminish risk; patients with high denial who did not complain of depression or tension had a higher risk for coronary disease, and patients with low denial who complained of fatigue had more morbidity at follow-up. Because of its variable effects on illness and its role in confusing the relationship between psychological state and disease, denial must be evaluated carefully.