During a three years period, 11 patients with clinically suspected aortic dissection were diagnosed by CT asthe primary mode of investigation. Chest roentgenography was performed in all 11 patients and ultrasonography wasperformed in 2 patients. None of them obtained aortography. The authors analized them and obtained the results asfollows: 1. 7 cases were female and 4 male , with a mean age of 65 years(range 53-75 years) 2. All of themsuffered from hypertension. The most consistent clinical symptom was severe tearing chest pain which was radiatingto back. ECG revealed the findings of LVH in all 11 cases. 5 cases were expired within 2 weeks and 6 cases treatedmedically with symptomatic improvement. 3. Chest roentgenography revealed suggestive signs of dissecting aorticaneurysm such as widening of superior mediastinum, shifting trachoea to the right side, obliteration of aorticknob, double aortic knob, displacement of intimal calcification and pleural effusion. 4. CT findings proffered ususeful informations which were double channel with intimal flap, displacement of intimal calcification, thrombosis, increased diameter of aorta, pleural and pericardial effusion, and narrowness of true lumen. 5. Theauthors recommend a CT study as the most important preliminary examination in all suspected cases of dissectingaortic aneyrusm even though it has some limitations.