Ocular ultrasonography in horses represents a valuable imaging diagnostic tool for the diagnosis of intraocular and periocular diseases, particularly when cornea or lens opacities preclude ophtalmoscopy of deeper structures. The authors studied normal and pathological aspects of the eye. Nineteen horses with opacities of the dioptric structures underwent an ultrasound examination. This technique allowed the diagnosis of a posterior synechia (1), cataracts (8), vitreous opacities (6), retinal detachment (3) and a foreign body (1). Ultrasonography provided helpful information about the structure and vascular pattern when the conventional ophtalmic evaluation was unable to achieve a correct diagnosis