Purpose: To report the success rate of endoscopically assisted balloon dacryoplasty (EADCP) for treatment of acquired incomplete nasolacrimal duct obstructions (NLDOs). Design: Retrospective, noncomparative case series. Participants: Records of patients treated for incomplete NLDOs with EADCP by one of the authors (WLW) were reviewed. Diagnosis of incomplete NLDO was based upon subjective complaints of tearing, dye disappearance testing, clinical evidence of epiphora, and nasolacrimal duct irrigation. Endoscopically assisted balloon dacryoplasty was performed for incomplete obstructions identified. Methods: One hundred forty-two nasolacrimal systems in 103 patients with incomplete NLDOs underwent EADCP for treatment of incomplete obstructions. A 3 x 15-mm balloon was utilized in all procedures, with silicone lacrimal tubes placed in 131 systems. Patients received postoperative topical antibiotic-steroid drops for 2 weeks and a 1-week tapering dosage of systemic methylprednisolone. Main Outcome Measures: Patients were assessed at their last postoperative visit by nasolacrimal system irrigation, dye disappearance testing, and subjective complaints of epiphora. Results: Eighty systems (56%) experienced complete resolution of symptoms after surgery. Forty-eight additional systems (34%) showed improvement but still experienced periodic epiphora. Fourteen systems (10%) showed no improvement. The average time before follow-up was 7.5 months. Conclusion: Endoscopically assisted balloon dacryoplasty as a treatment for incomplete NLDOs provides complete relief or substantial improvement in a significant percentage of patients. Nasal videoendoscopy adds significantly to the understanding of this procedure and its potential for success. Endoscopically assisted balloon dacryoplasty should be considered an appropriate treatment option for selected patients with incomplete NLDOs.