Woven coronary malformation is characterized by the branching of a major epicardial coronary artery into thin channels which then merge again in a normal conduit. The angiogram can suggest a filling defect instead of a malformation and an undue coronary angioplasty could be performed determining some damage to the arterial wall. In this case report we describe a patient with a stenosis on the left anterior descending coronary artery and a woven coronary artery on the right coronary artery. In 1995 a coronary angioplasty was performed on the left anterior descending coronary artery. Four years later a coronary angiogram did not show any changes in the right coronary artery. In this patient the malformation did not induce any reduction in the coronary reserve as shown at cardiac scintigraphy. We need more information about the natural history of such a malformation.