Purpose: To evaluate the efficacy of the Ritleng lacrimal intubation system in the treatment of congenital nasolacrimal duct obstruction. Methods: Twenty-six patients (29 eyes) with congenital nasolacrimal duct obstruction, who ranged in age from 2 to 12 years (mean, 4.85 +/- 2.9 years), underwent silicone intubation with the Ritleng lacrimal intubation system. The Ritleng lacrimal intubation system is composed of a Ritleng probe, a monofilament guide thread and a silicone tube. The prolene tip was removed from the inferior meatus with nasal endoscopy in 26 eyes, whereas this was done by using a Ritleng hook in 3. Clinical success was defined by the relief from symptoms and signs of obstruction. The tubes were left in place for an average of 6 months. The patients were followed up between 6 and 25 months (mean, 8.3 months). Results: All cases were successfully intubated with the Ritleng system. Two cases underwent reintubation because of tube dislocation during the first week. Granuloma developed at the edge of the inferior punctum in 1 case. We observed relief from symptoms in all cases. Conclusion: The Ritleng lacrimal intubation system is an easy, effective and nontraumatizing procedure for the treatment of congenital nasolacrimal duct obstruction. Copyright (C) 2004 S. Karger AG, Basel.