In 2017—2018, the authors examined and operated on 35 patients aged 20 to 39 years (19 women, 16 men) with cystic maxillary sinusitis. The study included patients who were diagnosed with retention cyst of the maxillary sinus, located on the lower walls of the maxillary sinus and dealing with no more than 2/3 of the maxillary sinus volume, according to CT of the paranasal sinuses. The operation was performed using the following method: two punctures of the sinus were performed simultaneously in a typical place in the lower nasal passage — using a Kulikovsky needle and using a 2.8 mm trocar. The fiber of the Ho-laser was inserted into the Kulikovsky needle, and an endoscope was inserted into the trocar in parallel with the 0, 30 or 45°. Then, under the control of the endoscope, the fiber was inserted into the cyst and given a series of impulses before its «explosion». The parameters Ho:YAG-radiation had the following values: power — 14.4 W, pulse energy — 1.2 Jol, pulse frequency — 12.0 Hz. All patients were discharged from the hospital on the 2nd day. In the long-term period (up to 14 months), according to the endoscopic examination, an objective examination and CT of the paranasal sinuses showed no recurrence of the cyst in any patient, no pathological changes were recorded in the area of the lower nasal passage.