Phlebothrombosis is a thrombus which develops within a vein. About 90% of phlebothrombosis takes place in the extremities and constitutes a risk factor for deep venous thrombosis, a lifethreatening disease. The occurrence of this lesion in the oral cavity is rare. To our knowledge, besides this case, there is only one previously reported case of tongue phlebothrombosis. Here, we report the second case in addition to a comprehensive discussion of the pathogenesis and potential risks of this uncommon lesion. Keywords: thrombosis, tongue, venous diseases