Based on two field trips undertaken in 2009 as well as a review of the literature, a checklist of the lichens and the lichenicolous fungi from El Hierro, the most southwestern of the Canary Islands, is presented. As a result, a total of 589 taxa are reported, including 278 new for the island of which 57 are new for the Canary Islands. In addition, 5 species are newly described in the genera Lecania, Lecidea, Protoparmelia, Solenopsora and Trinathotrema. The number of novelties reported here indicates that El Hierro is exceedingly under-recorded for the lichens and the lichenicolous fungi. Terricolous, saxicolous, as well as corticolous species are recorded, but foliicolous lichens have not been found. Notes are given on ecology and sometimes on morphology and chemistry.