The significance of coronary artery calcification was assessed in 800 patients who underwent cardiac fluoroscopy and selective coronary cineangiography. Calcification was shown by fluoroscopy in 250, of whom 236 (94%) had greater than or equal to 75% stenosis of one or more major coronary arteries at angiography. Among patients with significant coronary artery disease, 40% (236/585) had calcification. Patients with calcification demonstrated poorer survival at all follow-up intervals (from six months to five years); the five-year survival rate was 87% for patients without calcification, compared to 58% for those with calcification. The prognostic significance of coronary artery calcification appears to be independent of information obtained by cardiac catheterization and angiocardiography.