This is a retrospective histopathological study of archive slides from the Comparative Ocular Pathology Laboratory of Wisconsin from 1981 to 1997. Reports on eyes or ocular contents from 2176 dogs were reviewed. Five-hundred and thirty out of 2176 (24%) of the cases had a clinical or histologic diagnosis of glaucoma. Twenty-five out of 530 (5%) of the canine cases of glaucoma were in Golden Retrievers. Thirteen out of 25 (52%) of the Golden Retriever cases of glaucoma had iridociliary cysts. Iridociliary cysts in Golden Retrievers may lead to the development of glaucoma. Histologically all 13 of the cases of glaucoma and iridociliary cysts had large thin-walled cysts lined with attenuated cuboidal epithelium filling most of the posterior chamber. The following histologic features were also present: thick walled cysts containing hyaluronic acid (8/13; 62%), a solid cellular proliferation (2/13; 15%), a retrocorneal membrane associated with a defect in Descemet’s membrane (7/13; 54%), iris bombé (5/13; 38%), a preiridal fibrovascular membrane (4/13; 31%), hemorrhage (4/13; 31%), a cellular membrane on the anterior lens surface (6/13; 46%), retinal detachment (5/13; 38%), peripheral anterior synechia (5/13; 38%), and posterior synechia (6/13; 46%). Complete follow up was obtained on 11/13 (85%) of the Golden Retrievers with glaucoma and iridociliary cysts. Two/11 (18%) of the dogs were euthanized due to intractable glaucoma. Eight/13 (62%) of the dogs had problems in the other eye. The other eye was diagnosed with uveitis 5/11 (45%), glaucoma 2/11(18%), pigment in the anterior chamber 3/11 (27%), and iridociliary cysts 4/11 (36%).