The platelet-rich plasma (PRP) has been applied to repair and regenerate different types of tissues. Currently, the use of platelet-rich plasma has demonstrated more and more effectiveness in the recovery of the lesion and in the gain of time in the treatment of the corneal keratitis or corneal ulcer in different species. The prevalence of traumas that affect the cornea in horses is high and represents the majority of ophthalmic injuries in this species. Due to its localization, it is more frequently subject to traumatic processes, such as corneal ulcer. The time it takes to make the diagnosis and start treatment may be decisive for the animal's prognosis. The aim of this study was to report a clinical case of ulcerative keratitis in a horse treated with platelet-rich plasma (PRP) associated with eye drops. A seven-year-old female horse was seen at an equestrian center, with a history of facial lesion evolving for six days, which was diagnosed as ulcerative keratitis. In the clinical exam the animal presented pain and intense agitation during the clinical evaluation besides corneal lesion, photophobia, blepharospasm, epiphora, conjunctival hyperemia, corneal edema, miosis and lacrimation. The animal was treated with autologous PRP and ophthalmic eye drops both with three TID drops. The PRP was obtained by collecting whole blood (80mL) by venipuncture of the right jugular vein in tubes containing sodium citrate, centrifuged and kept under refrigeration. During the treatment, antalgic therapy was performed using non-steroidal anti-inflammatory and the animal was kept with a tampon during the 15 days of treatment until the evolution of the case and the beginning of healing of the lesion site, demonstrating the efficacy of PRP treatment.