Among 100 patients who underwent cardiac catheterization for acquired valvular disease, selective coronaryangiography showed in 25 cases obstructive changes of coronary arteries, in many instances of such severity to modify the therapeutic program (myocardial revascularization associated with valvular repair, counter-indication to surgical therapy). Coronary artery alterations were discovered in patients without clinical and electrocardiographic signs of coronary insufficiency, and, on the contrary, normal coronary tree was found in patients with positive clinical and electrocardiographic findings. The importance of coronarography in the haemodynamic study of valvular patients is stressed, even in absence of evident clinical signs of coronary insufficiency. The preoperative evaluation of the coronary arteries is fundamental for a correct surgical indication and for the results of surgical therapy.