We studied 100 consecutive patients with coronary angiography performed after a positive result of a non-invasive test in the chest pain unit. Mean age was 66 years. The percentage of patients without significant coronary artery disease, 1-vessel disease and multivessel disease was 35, 33, and 32%, respectively. The CPU-65 index that combines four clinical variables (comorbidity: diabetes, pain: typical, use of: aspirin, 65 years old or more) was associated with the presence of coronary artery disease, multivessel disease, and coronary revascularization. We conclude that in the chest pain unit, patients with a positive non-invasive test the rate of false positive results, one-vessel disease and multivessel disease is similar. However, important changes in these percentages are seen, according to the clinical profile. The CPU-65 index is useful to determine the pre-test probability of significant coronary artery disease and patients with intermediate scores are the ones that benefit most of non-invasive tests.