In order to compare long-term-results of revision sinus surgery with the results of primary sinus surgery, the charts of 226 patients were reviewed 17-72 months (mean 42.3 months) after endonasal microsurgical ethmoidectomy or sphenoethmoidectomy, respectively (primary operation, n = 135; revision operation, n = 91). Additionally, 203 of the patients were asked to subjectively evaluate the success of the sinus surgery by means of a questionnaire. Responses were received from 67.5% of the patients (primary operation, n = 82; revision operation, n = 55). Eighty-three percent of the primary group and 82% of the revision patients felt that their operations had been successful, whereas the remaining patients thought it to have been a failure. The most frequent complications were temporary post-operative edema or hematoma of the lower eyelid, the complication rate being 8.8% in both groups. No serious complications were observed. Additionally, it was found that the results of endonasal sinus surgery did not depend on the medical history of the patient, preoperative CT findings, or the surgical techniques employed. These findings suggest, that despite all diagnostic and therapeutic tools being available at present we still cannot prohibit, that after sinus surgery 15%-20% of patients will develop recurrent sinus polyposis, and are unable to predict, in which patient and at what time the disease will recur. From this point of view the availability of an almost atraumatic sinus surgery by means of an endonasal (microscopic or endoscopic) approach is definitely a great advantage for patients with chronic sinus disease.