Sixteen cases of malignant sinonasal tumor that had underwent resection of primary site with orbital exenteration were reviewed. The most common tumor was maxillary cancer of 12 cases, and it was confirmed that the madial wall of orbit was most commonly involved in ethmoid cancer and the inferior wall in maxillary cancer. Computed tomographic evidence of orbital invasion was remarkably well correlated with that of the histological findings(15/16 : 93.8%). Our study confirms that the computed tomography is a useful technique to detect the orbital invasion and an essential diagnostic tool in preoperative planning of reconstruction after orbital exenteration.