Brain diseases in the horse are rare. The diagnosis, spread of the pathology and any possible planning of the surgical treatment can be made using MRI. Some congenital diseases like Dandy-Walker-Like Syndrome and hydrocephalus give a typical MRI image, just like hemorrhage, edema and infection. A tumor, hematoma, cyst and abscess are space occupying processes that have each their own specific qualities and each giving a specific image on T1 and T2. The tumors most frequently seen are cholesterinic granulomas in the choroid plexus, hypophysis tumors and metastases from the nose, the sinuses, the eye or other primary tumors in the body. MRI is the only ante mortem technique that can be used for the diagnosis of equine nigropallidal encephalomalacia.