BACKGROUND The aim of this work is to investigate the prevalence and clinical characteristics of congenital lacrimal fistula in Down syndrome patients. METHODS The medical records of 198 Down syndrome patients who were referred to a tertiary ophthalmology clinic from 2000 to 2010 were retrospectively reviewed to identify patients with congenital lacrimal fistula. The demographic data, clinical features, clinical management, and clinical outcomes were recorded. The main outcome measures were the presence and laterality of fistula, accompanying adnexal and oculomotor abnormalities including congenital nasolacrimal duct obstruction (NLDO), the type of surgery performed, and surgical outcome. The prevalence of congenital lacrimal fistula in Down syndrome patients was calculated upon this data. RESULTS Congenital lacrimal fistula was identified in 8/198 (4.04 %) patients, 4 (2.02 %) of whom presented with bilateral lacrimal fistula. All patients that had lacrimal fistula complained of tearing from their eyes. Congenital NLDO was observed in seven of eight patients with lacrimal fistula. Five patients underwent excision of the lacrimal fistula for the improvement of cosmesis, and three of these patients also underwent lacrimal silicone intubation for NLDO. Another patient received lacrimal silicone intubation for NLDO without excision of the lacrimal fistula. Excision of the lacrimal fistula was successful in all patients; however, tearing persisted after surgery in two patients with uncorrected NLDO. CONCLUSIONS Congenital lacrimal fistula occurs more frequently in Down syndrome patients and therefore these patients should be thoroughly examined for this abnormality. Down syndrome patients with congenital lacrimal fistula should be also examined for NLDO, because this condition is frequently observed in these patients.