Computed tomographic findings in fifteen cases of anterior mediastinal teratoma are presented and comparedwith radiographic , pathologic findings. Specific CT characteristics of anterior mediastinal teratoma arepredominantly fatty mass with a denser dependent element and globular calcification in a solid protuberance intothe cystic cavity. Six cases presented above described characteristic CT findings. Four cases presented waterdensity mass with surrounding thick wall. Fat and calcific densities were present in nine and seven respectively,so these findings are frequently absent. Thick wall was present in all cases. So thick walled cyst even in theabsence of fatty or calcific densities is highly suggestive of anterior mediastinal teratoma.