A rare case of telangiectatic osteosarcoma of the sphenoid bone was reported. The patient was a 27-year-old male and had suffered from left eye protrusion and diplopia for three months. Radiologically, a lobulated osteolytic lesion was located between sphenoid and left temporal bone. Pathologically, the tumor had multiloculated blood filled cystic vascular spaces and osteoid formation by malignant spindle osteoblast cells. The differential diagnosis of this rare entity from aneurysmal bone cyst was important radiologically and pathologically. This case is the second case of telangiectatic osteosarcoma of the sphenoid bone followed by a case of Whitehead RE and Melhem ER in 1998.