There is no doubt that there is a considerable number of cases of acute and chronic sinusitis, which can be cured only by surgical intervention. The modern philosophy should be: to choose a surgical technique as conservative as possible and as radical as necessary according to the individual case. To achieve this goal, an exact knowledge of the anatomy and pathology of the paranasal sinuses, as well as a full command of the available diagnostic methods (including sinuscopy) are essential. The sometimes dangerous complications of acute ethmoiditis in children usually can be solved by simple displacement of the middle turbinate to the center and uncapping of the ethmoidal cells assisted by antibiotic and antiphlogistic treatment. The surgical treatment of choice in cases of acute recurrent or chronic maxillary sinusitis in children (often combined with bronchial or allergic problems) is the installation of a nasoantral window from the inferior meatus, to guarantee adequate drainage. In adults, the radical techniques of Caldwell-Luc (maxillary sinus) and Riedel (frontan sinus) should be used in selected cases only. They should be replaced--if possible--by osteoplastic methods or modified techniques (frontal and maxillary sinus) or bimeatal-transnasal approach under endoscopic control (maxillary and ethmoidal sinus). Healthy and reversibly damaged mucosa should be saved; but at the cost of sacrificing the nasal function instead.