Snapping hip is a polymorphous pathology the genesis of which is multifactorial, characterized by a snapping sensation which may be painful, and occurring during movement of the hip or during walking. Clinical and instrumental diagnosis for an accurate etiopathogenetic classification is essential to correct surgical treatment, that must be reserved only for cases with painful symptoms and with disorders in walking. The authors provide a classification system of the syndrome, describing four different varieties of the pathology and relative surgical treatment.