Inflammation, infection and adhesions of the lacrimal sac caused by the obstruction of the lacrimal duct, as well as repeated treatment with tubes and lasers, often result in adhesions and atresia of the lacrimal sac, and symptoms such as tearing and pus overflow cannot be relieved or cured despite repeated treatment. This type of patient often occurs more often in women. Surgery is the last resort to treat such diseases, but the original trans-facial incision leaves scars that are often difficult for patients to accept. We perform a transnasal lacrimal sac nasal anastomosis, which leaves no tube in the lacrimal duct of the eye after surgery and leaves no scar on the surface. The patient, a 37-year-old female, had been suffering from tearing in the wind and pus in the corner of the eye for many years, and had been treated repeatedly with probe dilation, laser, and down-tubing, but it did not improve, but got worse. We performed a CT scan after lacrimal sac imaging and found that the left lacrimal sac had been severely reduced in size and the contrast was not flowing into the nasolacrimal duct and nasal cavity, as shown in Figure 1. On the right side, the same imaging showed that no contrast remained in the lacrimal duct, indicating a patent lacrimal duct. We performed endoscopic lacrimal sac nasal anastomosis on the third day of admission. Intraoperatively, severe lacrimal duct and lacrimal sac adhesions were seen. A channel was created between the residual lacrimal sac cavity and the nasal cavity, and the procedure was completed. The patient was discharged 2 days after surgery and the anastomosis was patent at 3-month follow-up. Figure 2 Intraoperatively A small window has been opened in the medial wall of the lacrimal sac and a metal probe inserted through the patient’s lacrimal punctum can be seen, indicating that the positioning of the lacrimal sac and the height of the window opening were able to meet the requirements for successful surgery.