The ocular ultrasonography in horses represents a valuable imaging diagnostic tool for the diagnosis of the globe, intraocular and periocular diseases, particularly when cornea or lens opacities preclude ophtalmoscopy of deeper structures. Moreover, when retrobulbar masses occur, ultrasonography is able to provide helpful information about the structure and the vascular pattern and to guide the withdrawal. Aim of this study is to define the indication for equine ocular ultrasonography and to obtain rapresentative ultrasonographic images of pathological clinical cases.