PurposeTo evaluate the long-term patency of lacrimal drainage system (LDS) after balloon dacryocystoplasty (BD) and to give the long-term success rates according to the severity and localization of the obstruction.MethodsBetween May 1993 and December 2003, BD was attempted in 117 eyes of 108 patients with idiopathic-acquired LDS obstruction. Patients with active dacryocystitis, dacryolithiasis, traumatic obstruction or lacrimal mass, obstructions at the superior or inferior canaliculi lateral to the common canaliculus, and follow-up period less than 36 months were excluded from the study.ResultsThe results of BD were evaluated in 99 eyes of 94 cases. The obstruction was seen at the common canaliculus in seven eyes, proximal nasolacrimal duct in 70 eyes, and distal nasolacrimal duct in 22 eyes. The mean follow-up period was 100.038.4 months (range: 36-142 months). The long-term overall success rate was 40.8% (20/49 eyes) in complete obstruction and 68% (34/50 eyes) in partial obstruction. The clinical success rate was 57.1% in common canalicular (complete: 33.3%, partial: 75%), 50% in proximal nasolacrimal duct (complete: 38.5%, partial: 64.5%), and 68.2% in distal nasolacrimal duct (complete: 57.1%, partial: 73.3%) obstructions. The overall success was 54.5% (54/99 eyes) for the entire series at the last clinical follow-up visit.ConclusionThe long-tem success rate of BD for the treatment of epiphora is low and is not comparable to conventional dacryocystorhinostomy. More predictable results can only be achieved in carefully selected patients and this procedure can be recommended in cases demonstrating partial obstruction of the distal nasolacrimal duct. © 2008 Macmillan Publishers Limited. All rights reserved.