This retrospective study was conducted in Cairo university hospitals and included 166 patients. Most of the patients were diagnosed with NLDO. The main complaint was excessive lacrimation. 65 % were female and 35 % were male.The aim of the study was to compare the effect of posterior lacrimal and nasal flaps on the outcome of external DCR. Patients were divided into two groups; group A in which the posterior lacrimal and nasal flaps were excised, and group B in which the posterior lacrimal and nasal flaps were excised.All patients had external DCR under general anaesthesia and were performed by highly experienced ophthalmologist. Patients were followed up for six months postoperatively. Postoperative data collection included disappearance of symptoms, presence of complications, and the results of regurge and irrigation tests at the end of the six months follow up period.