The objective of the present work was to develop a technique for the endonasal surgical access to the maxillary sinus through crista conchalis of the maxillary bone and to evaluate the effectiveness and safety of the surgical treatment by this method. A total of 210 patients underwent the CT-assisted examination of the paranasal sinuses. The data obtained made it possible to characterize the detailed anatomical structure of crista conchalis of a maxillary bone that forms the anterior part of the medial wall of the maxillary sinus. The syntopy in relation to the distal end of the nasolacrimal canal and the cavity of the maxillary sinus was investigated. The results of the study were used to develop the original technique for endonasal antrotomy that included the 0.5—1.0 cm long vertical section of the mucous membrane at the level of the anterior end of the inferior turbinated bone approximately 1 mm from the edge of the bone aperture of the nose which exposed crista conchalis up to the place of fixation of the inferior turbinated bone. Then, the diamond drill burr was use to carry out trepanation of the medial wall of the maxillary sinus in the region of crista conchalis of the maxillary bone; sanitation of the of the sinus was followed by the apposition of the edges of the incision and their fixation with two sutures. The safety of the proposed surgical technique was confirmed by results of the repeated CT examinations of the paranasal sinus and its effectiveness by the clinical follow-up observations.