This paper reviews the literature evidence on the herbivore-kelp interactions along the Chilean coast, basically the role of sea urchins and gastropods in the structure of rocky shallow subtidal marine communities. Due to the morphology of the Chilean coast, we divided our analysis in two large zones. In northern Chile, between 18 degrees-42 degrees S, the Cordillera de la Costa runs close to the coast generating extremely exposed habitats. In this zone two species of Lessonia are dominant in intertidal and subtidal habitats. Here, the sea urchin Tetrapygus niger is the most abundant grazer producing extensive intertidal and subtidal barren grounds. South of 42 degrees S to Cape Horn, Macrocystis pyrifera forms the most conspicuous kelp association in a fjord zone, where hundreds of islands produce protected habitats. Four species of sea urchins and the gastropod Tegula atra graze on M. pyrifera. However, their effects are spatially and temporary restricted. The foraging behavior of the principal herbivore, the sea urchin Loxechinus albus, is influenced by the degree of wave action, restricting its effect to exposed areas, In very protected areas Tegula atra affects the population dynamics of M. pyrifera.