A case of congenital scleral staphyloma was treated with a preserved homologous peritoneum graft. A 2-year-old female poodle with a blue-gray mass in a dorsal and temporal position of the sclera of the left eye was evaluated. The repair of the scleral defect with a graft of preserved homologous peritoneum reduced the strabismus and the size of the staphyloma, and improved the cosmetic appearance of the eye.