Ninety-nine patients with chest pain and a presumptive diagnosis of coronary heart disease were assessed blindly within 24 hours of angiography, using standardized psychiatric and social interviews and a personality inventory. Thirty-one patients had normal coronary arteries (NCA), 15 had slight disease and 53 had significant coronary obstruction. Twenty-eight (61%) of the 46 patients with insignificant disease and 12 (23%) of the 53 with significant obstruction had psychiatric morbidity. Associations between the overall severity of psychiatric morbidity and measures of social maladjustment were strongest in the patients with normal coronary arteries. The 26 men with insignificant coronary artery disease had higher scores of neuroticism and extraversion than the 41 with important coronary occlusions. No differences were observed when the same comparisons were made for the women. The findings indicate that approximately two thirds of patients with normal and near-normal coronary arteries have predominantly psychiatric rather than cardiac disorders: the symptoms in these patients are more likely to represent the somatic manifestations of anxiety and overbreathing than the consequences of underlying cardiac disease. Physicians should be aware of the ways in which neurotic illness may present with symptoms mimicking cardiac disease, especially when cardiovascular symptoms are accompanied by phobic symptoms and unexplained shortness of breath.