PURPOSE: To evaluate the feasibility and long-term outcome of the use of self-expandable metallic Z-stents inthe canine lacrimal sac. MATERIALS AND METHODS: Stents were constructed using 0.1 mm stainless steel wire in acylindric zigzag configuration of four bends; their diameter when fully expanded was 2.4 to 3mm, their length was6.0 to 8.0mm, and they were coated with 24-karat gold. Under fluoroscopic guidance and using a 3F cutdown tube, atotal of 12 stents were placed in 12 lacrimal sacs of six adult dogs, which were observed for tearing. After onemonth to three years of observation, the dogs were sacrified and examined grossly and histologically. RESULTS: Stent placement was technically succussful and well tolerated in all but one lacrimal sac, in which the stent wasmisplaced. At three and six months after stent placement, stent wires were not encased by epithelium, but at ninemonths, and one, two and three years after placement, six of the 12 stents had become encased in a proliferationof this where the stent wires contacted the lacrimal sac wall. In no lacrimal system in which stent placement hadbeen successful was migration, stenosis or obstruction of the lacrimal system observed. One misplaced stent causedobstruction of the lacrimal sac, however. CONCLUSION: In 11 of 12 case (92%), fluoroscopic placement of anexpandable metallic stent in the canine lacrimal sac was successful; in 6 of 8 cases (75%), the stent wires becameencased by a proliferation of mucosa, but during long-term follow-up of 9 months to 3 years, no obstruction wasobserved.