Detailed studies on the lichen genus Porina in Macaronesia have led to a reappraisal of the genuine identity of Porina atlantica (Erichsen) P. M. Jørg., a characteristic species that has previously been confused with P. guaranitica, P. heterospora, P. nucula, P. mastoidea or P. rhodostoma in the literature, and is here reported from Madeira, the Canary Islands, Ireland, France and Portugal. Two new species are described: P. effilata Brand & Sérus. sp. nov. (known from Madeira, the Canary Islands, Great Britain, Ireland and Portugal) and P. ocoteae Brand & Sérus. sp. nov. (restricted to La Palma, Canary Islands, and São Jorge in the Azores). Porina leptospora Nyl. is recognized at the species level, and P. isidiata Kalb & Hafellner is reduced into synonymy with P. atlantica. A key to all known species of Porina in Macaronesia is provided.