Three new species of longhorned beetles (Coleoptera: Cerambycidae) from Central and South America are described and illustrated: Strangalia yoryinethae sp. nov. and Strangalia lourdesae sp. nov. (Lepturinae: Lepturini), both from Monteverde, Costa Rica; and Peritrox shanebouchardi sp. nov. (Lamiinae: Onciderini) from Paraguay. In addition, a key to the known species of Peritrox Bates, 1865 is provided.