We evaluated the association between coronary spasm and hyperinsulinemia (high immunoreactive insulin, IRI) in patients with angina pectoris. The study cohort comprised 30 patients with spastic angina pectoris, 30 patients with angina pectoris showing fixed-obstructive coronary sclerosis and 30 control subjects who were matched for body mass index, age and sex. A 75-gram oral glucose test was performed, and blood sugar and IRI were serially measured concomitant with serum total cholesterol, triglyceride and HDL cholesterol. The IRI level at 60 min, the peak IRI during the test, Σ IRI and ΣIRI/Σ blood sugar were significantly higher in the patients than in the controls. Total cholesterol and LDL cholesterol levels were significantly increased in patients showing fixed-obstructive coronary sclerosis compared to controls.