Corneal sequestrum is a common condition in cats, rarely reported in other species. Brachycephalic breeds including the Persian, Himalayan and Burmese appear to be predisposed. It is characterised by an area of brown to black discolouration of the corneal stroma, with or without overlying corneal ulceration. Light and transmission electron microscopy studies have revealed necrotic keratocytes and disarranged collagen. The cause of the brown discolouration remains unclear, and the pathogenesis is not fully understood. Feline corneal sequestrum is known to occur after chronic corneal ulcers or keratitis caused by FHV-1 and following keratitis caused by entropion. The treatment of choice for corneal sequestrum is surgical excision (keratectomy) +/- repair of the cornea using techniques such as corneoconjunctival transposition or conjunctival grafts. This presentation covers how to recognise corneal sequestrum, considers underlying causes, and discusses the treatment options.