Chiari type I malformation (CIM) was first described in the late 19th Century. However, it still raises a great interest among the scientific Community because of the increasing number of diagnosed cases, the still unclear pathogenesis and natural history and the different options in the surgical management. The present review aims at analyzing the centenary history of CIM, starting from the first description done by Hans Chiari to the more recent classification, in order to introduce such a complex disease and to show the way followed for its assessment over the time.