With chronic maxillary sinusitis the pathological changes in the diseased mucosa used to be considered irreversible, thus necessitating its radical removal, which is only possible with the Caldwell-Luc operation. The discovery of the reversibility of the pathology caused a shift from the Caldwell-Luc towards endonasal procedures, of which the inferior meatal antrostomy became the most widely used. Nasendoscopy, later combined with computed tomography, led to the development of the concept of the osteomeatal unit, and hence the functional endoscopic sinus surgery, which is concentrated round the infundibulum region. In view of possible risks and complications of that method it is propagated here to differentiate between these two techniques: When the focus of chronic sinusitis appears to be situated in the infundibulum/anterior ethmoid region, the functional endoscopic surgery seems preferable; For cases where the inflammatory process was restricted largely to the maxillary sinus a modified inferior meatal antrostomy technique proved to have a 92% success rate in 378 sinuses.