The Araripe Plateau is situated in the states of Ceará, Piauí and Pernambuco, northeastern Brazil, in the Caatinga biome, semiarid domain. This region of Brazil is characterized by high temperatures and low rainfall. Nevertheless, due to its high elevation and large amount of orographic rainfall, the Araripe Plateau is an exception as a seasonal semi-deciduous forest with high humidity in the semiarid domain and the Caatinga biome. Herein a species list of Araripe Plateau arachnids is presented from the compilation of data from in situ sampling from January to May 2013, from the literature, and from Brazilian arachnid collections data. A total of 68 species were recorded for the area, of which 53 were spiders, eight harvestmen and seven scorpions. The species richness recorded here is considered significant regarding the known diversity of Arachnida in the semiarid region and contributes to expanding our knowledge of the area.