In the present work, 12 species of Cumulopuntia are reported for the Department of Arequipa, Peru. Three new combinations are made: Cumulopuntia dimorpha, C. ignota, and C. unguispina, the last two correspond to corrections on former combinations, invalid according to the nomenclatural code. Neotypes are designated for Opuntia dimorpha, O. unguispina, Tephrocactus mistiensis, T. multiareolatus and lectotypes for Opuntia ignota and O. rauppiana. This work presents a key to the species present in Arequipa, together with field pictures and illustrations; the taxonomy of each species is also discussed.