Internal jugular phlebectasia is abnormal fusiform or saccular dilatation of the jugular venous system and usually presents as a neck mass that increases in size with maneuvers, which increase intrathoracic pressure. Clinically internal jugular phlebectasia is self limited benign condition and usually no treatment is required after initial diagnosis. So suspicion of this disease and appropriate diagnostic approaches are essential to avoid unnecessary surgical intervention. Authors present 2 cases of the neck mass which were confirmed as the internal jugular phlebectasia. The chief complaint was fluctuating neck mass on Valsalva maneuver and there was no associated symptoms. Ultrasonography and Doppler technique confirmed those masses were engorged internal jugular veins.