The etiology of primary nasolacrimal duct obstruction is largely unknown, and this disease may occur bilaterally in a small percentage of patients. In this retrospective study, the authors aimed to discuss the cost, operation time, complications, and success rate of simultaneous bilateral endonasal endoscopic surgery. Twenty-eight patients (16 female, 12 male) were enrolled in this study, with a mean age of 55 years old (range: 43–76). The success rate was 91% (51/56), and the mean operation time was 44 minutes. Only minor and transient complications were observed in 2 of the patients. Overall, the authors believe that a bilateral endoscopic dacryocystorhinostomy would be useful in a single session, based on its advantages of low morbidity, low cost, and high success.