Arteriovenous fistuli are congenital malformations. Usually symptoms depend on size of the lesion. Lesions smaller than 2 cm are often asymptomatic. The most common symptoms are dyspnea, palpitation and fatigue. Cyanosis is indicative of right to left shunt. Helical computed tomography (CT) scan is a helpful diagnostic tool in this case. Surgery is the treatment of choice in patients with isolated lesions. Embolization is a selective method in patients with multiple or bilateral lesions. The patient was a 13-year-old boy complaining of cyanosis of lips and nails as well as dyspnea for 5 years. Definite diagnosis of pulmonary arteriovenous malformation (PAVM) in the right middle lobe was based on CT angiography. The patient underwent a thoracotomy and lobectomy of the right middle lobe. After surgery cyanosis and dyspnea were completely resolved.