Objective: To investigate computerized tomography (CT) data of patients who needed revision surgery for chronic rhinosinusitis. Material and Methods: 83 patients who underwent revision endoscopic sinus surgery by the senior author due to recurrent and/or persistent chronic rhinosinusitis were included in this study. The following data were obtained from preoperative CT scans and recorded for each side of every patient: recurrent polyposis, incomplete uncinectomy, retained agger nasi cell, lateralization of middle turbinate, recirculation phenomenon, maxillary antrostomy stenosis, incomplete anterior and posterior ethmoidectomy, scarring at the frontal recess, sphenoid ostium stenosis, or novel onset sphenoid disease. Results: Based on our findings, septal deviation caused inadequate posterior ethmoidectomy, while incomplete uncinectomy increased the risk of frontal sinus disease. Conclusions: We suggest that septum deviation may cause insufficient visualization, while incomplete uncinectomy may prevent adequate intervention to the frontal sinus and these subsequently play a role in ESS failure.