SUMMARYObjectiveCongenital nasolacrimal duct cyst (NLDC) is a rare disorder, which can present with ophthalmological and nasal signs and symptoms. The authors analyse their personal experience to identify diagnostic criteria for NLDC, which were treated by endoscopic transnasal procedure.MethodsClinical records of patients with a diagnosis of NLDC were retrospectively reviewed. All patients underwent rhinoscopy and ophthalmologist evaluation before surgery, whereas imaging was performed in selected cases. All neonates underwent transnasal endoscopic marsupialisation after failure of conservative medical therapy.ResultsFive patients were included in the study. One patient presented bilateral NLDC. In 3 cases, CT scan of the sinus was carried out. A total of 6 marsupialisation procedures were performed and a bi-canalicular lacrimal stent was positioned in 1 case. Complete remission of symptoms was observed in all cases.ConclusionsNasal endoscopy is mandatory to diagnose NLDCs, and, in some cases, it can be complemented by radiological procedures. When symptoms persist after systemic and topical therapy, nasal endoscopic marsupialisation is the treatment of choice. This surgical procedure is effective, safe and can be repeated if needed.