Under the term of olivopontocerebellar atrophy different nosological pictures are grouped, all characterized by showing clinical signs of deficiency of the structures of the pons and of the cerebellum. The diagnosis of olivopontocerebellar atrophy has been made, until now, by clinical criteria while typical anatomopathological changes are found at the autoptic studies. We describe three patients affected by olivopontocerebellar atrophy, of different types and at different stages of disease. In all cases MRI showed a similar and typical picture of atrophy of the olivary eminences of the medulla oblongata resulting in straightening of the angle usually present on the ventral frontier between pons and medulla oblongata. This diagnostic tool demonstrated thus to be of primary relevance yet in the early phases of the disease.