Arteriovenous malformations are vascular anomalies containing a communication between artery and vein without an intervening capillary bed and also are the most dangerous of vascular malformations being hemodynamically active. Treatment must be careful usually limited and considered in the phase of activity of hemodynamics. The patient was 29-year-old female and had no specific signs and symptoms except buldging, pal- pable mass on the right posterolateral chest wall from several years ago and it was gradually growing from that time. The operation was done with ligation of the right 9th, 1 Oth intercostal arteries and dissection from other normal tissues and then excised the arteriovenous malformation mass and its feeding vessels. The pathologic result was arteriovenous malformation.