Since the advent of computerized tomography(CT), it has played an essential role in the evaluation of the traumatic and tumorous conditions of the paranasal sinuses. But, in the realm of the infectious paranasal sinus disease, there have been only a few articles in journal publications, except those on the complication of sinusitis. Authors reviewed the CT scans of 26 patients with paranasal sinusitis and 9 cases with recurrent sinusitis and obtained the following results : 1) In total 26 patients with sinusitis, bilaterality was seen in 20 patients, among whom 10 patients had pansinusitis. 2) The distribution of sinusitis were 26 patients(100%) in maxillary sinus, 23 patients(88%) in ethmoid sinus, 12 patients(26%) in frontal sinus, 11 patients(42%) in sphenoid sinus. 3) The CT findings of sinusitis were variable patterns of the mucosal reaction, small size of the maxillary antrum(20/26), and thickened antral bony wall(25/26). 4) The changes in the ostium of the maxillary sinus, such as irregular bone erosion or ostial widening, were seen in 19 patients. 5) The usual findings of postoperative recurrent sinusitis were bony defect at anterior and/or medial wall of maxillary antrum, markedly contracted maxillary antrum and markedly thickened antral bony wall.