Endonasal dacryocystorhinostomy can be performed under general or local anesthesia. An area of 10 mm² anterior to the attachment of the middle turbinate on the lateral nasal wall is infiltrated with 2 % lidocaine with epinephrine (1 in 200,000) till mucosal blanching is evident. The nasal cavity is decongested for 5 min with a nasal pack soaked in 0.05 % oxymetazoline nasal drops. The surgeon positions himself on the contralateral side, that is, on the right side of the patient to do a left endonasal dacryocystorhinostomy. After punctal dilatation with a Nettleship dilator, a 23G vitrectomy light pipe is gently introduced (Fig. 23.2a, b) through the upper canaliculus until a hard stop is felt. A self-locking nasal speculum with 5 cm long blades is then introduced into the nasal cavity with the blades of the retractor placed vertically in the nostril and locked in a dilated position with the length of the speculum draped across the face, allowing self-retraction. The transillumination effect of the sac can be easily seen in the lateral nasal wall. A myringotomy sickle knife is used to incise the lateral nasal mucosa (Fig. 23.2c, d) showing maximal transillumination effect. The incision for the mucosal flap is begun 8 mm above the insertion of the middle turbinate and is then carried out vertically or in a curvilinear fashion down to the bone. A Freer’s or Cottle’s periosteal elevator is used to elevate the incised nasal mucosa and expose the frontal process of the maxilla and its articulation with the lacrimal bone. The posteriorly hinged nasal mucosal flap is excised (Fig. 23.2e, f) with Weil-Blakesley forceps. Once the lacrimal fossa is exposed, the thin lacrimal bone is elevated off the posterior half of the lower lacrimal sac up to the insertion of the uncinate process. With the use of a 3 mm forward-biting straight Kerrison ronguers (Fig. 23.2g, h), the thick bone of the frontal process of the maxilla is sequentially removed. The osteotomy is gradually enlarged superiorly so that the light pipe held horizontally can easily be seen tenting the lacrimal sac from within the nasal cavity, confirming that bone has been removed to the level of the common internal punctum. Any residual bone that appears dark against the bright red transillumination of the lacrimal sac needs to be meticulously removed. Finally the medial wall of the lacrimal sac is incised (Fig. 23.2i) with a myringotomy sickle knife while the lacrimal sac is tented by a light pipe and a large posteriorly hinged lacrimal mucosal flap is created. The overhanging edge of the lacrimal mucosal flap is trimmed with Blakesley forceps to create a marsupialized sac. Irrigation (Fig. 23.2j) is done to check for the patency of the drainage system. Bicanalicular silicone tubes are introduced through the canaliculi, retrieved and secured by two square knots in the nasal cavity. A prospective randomized trial currently underway by one of the authors (PJD) appears to show that the lacrimal stents may be an unnecessary step.