Mondor's disease is an uncommon condition characterized by a palpable, cordshaped structure, which causes pain when pressed. Its known pathophysiology is thrombophlebitis of the superficial venous system. Although reported repeatedly, its definite cause is unknown and various possible causes have been identified, including surgery, irradiation, infection, malignancy, and trauma. We diagnosed this case to be Mondor's disease of the antecubital venous system, probably due to thermal injury of the proximal tributaries of the basilic or cephalic vein. Risk of thermal injury to the skin flap or the portal site remains a common complication, and as thermal injury to the blood vessel might also be considered, attention must be given when suctioning the area near a large superficial vessel.