We report a case of acute left main coronary artery subocclusion treated by stenting. The patient had a severe ostial left main coronary artery stenosis and after diagnostic coronary angiography developed subocclusion of the left main coronary artery, with TIMI 1 flow and life-threatening hemodynamic consequences. After two balloon dilatations had failed, a half Palmaz-Schatz stent (7 mm) was successfully deployed at the site of the lesion with immediate improvement of the angiographic and clinical picture. We claim that the placement of a half Palmaz-Schatz stent, hand-crimped on a high-pressure and non-compliance balloon, could provide a means for restoring adequate blood flow in patients who develop an important ischemia after diagnostic coronary angiography of a short, calcified left main coronary artery with severe ostial stenosis. Despite the satisfactory angiographic and clinical findings in these patients, the risk of restenosis and the presence of other multivessel diseases press us towards a more definitive surgical treatment.