Pulmonary arteriovenous malformation (PAVM) is an anomaly condition characterized by abnormal vascular communications between arteries and veins in the lungs. Hereby we describe a 60-year-old female with PAVM. Although the patient was asymptomatic, an abnormal round opacity was found on a chest X-ray film. Computed tomography (CT) of the lung disclosed nodules connected with enlarged vessels. Because PAVM was suspected, the patient was further evaluated by spiral CT coupled with three dimensional reconstruction of the images (3D-CT). As a result, PAVM was clearly visualized and invasive procedures such as angiography was not performed. The present case illustrates that 3D-CT is a diagnostic procedure of choice when PAVM is suspected.