Herein, we present a revision of Periboeum Thomson, 1864 and its species, which are redescribed based on a detailed morphological study of exoskeleton. In addition, two new species are described from Brazil: Periboeum birai sp. nov. from the Caatinga biome (Bahia state) and Periboeum santossilvai sp. nov. from the Amazon biome (Pará and Amazonas states). The following synonymies are also proposed: P. acuminatum (Thomson, 1861) = P. atylodes Salvador, 1978 syn. nov.; P. ocellatum Gounelle, 1909 = P. maculatum Magno, 1987 syn. nov.; Sphaerion inerme White, 1853 = P. aduncum Napp & Martins, 1984 syn. nov. The following new combination is also proposed, Mephritus paucispinum (Lameere, 1890) comb. nov. (previously allocated in Periboeum). Additionally, we present new distributional records for P. obscuricone, Martins & Monné, 1975 (Peru and Argentina), P. terminatum (Perroud, 1855) (Uruguay), and P. vicinum (Perroud, 1855) (Bolivia). An updated key, photographs of all species (including types, when available), distribution maps, scanning electron microscopy images and schematic drawings are provided. Through this study, we conclude that transversal wrinkles near the posterior margin of pronotum (in some species, it is present on the entire pronotum) should be included as a new diagnostic feature for the genus.