Blattidae Latreille is widely distributed worldwide and includes a variety of sanitary pests, such as Periplaneta americana (Linnaeus), Periplaneta australasiae (Fabricius), and Periplaneta fuliginosa (Serville). The subfamily composition of Blattidae has undergone significant changes in recent years, and a few long-standing controversies have been resolved. However, the paraphyly of Blattinae Latreille, and the polyphyly of Periplaneta Burmeister within the subfamily, remain unresolved. We addressed these issues through phylogenetic analyses of the Blattinae based on mitochondrial genomes and nuclear genes (18S and 28S), and morphological analyses of nine male genital characters. Our study showed that Dorylaea Stål and Nazgultaure Lucanãs are sister taxa and distantly related to Blattinae. Periplaneta s.l. was found to be widely polyphyletic across five or six separate clades, while Mimosilpha Bey-Bienko was embedded within Homalosilpha Stål. Integrating ancestral character state reconstruction (ASR) analyses, morphological character comparisons, and our phylogenetic results, we propose five new genera (Unihamus Luo & Wang, gen. nov.; Fortiblatta Luo & Wang, gen. nov.; Arcicaulis Luo & Wang, gen. nov.; Tenumembrana Luo & Wang, gen. nov.; Crescispina Luo & Wang, gen. nov.) to revise Periplaneta s.l. We describe two new species (Hobbitoblatta semialata Luo & Wang, sp. nov. and Crescispina qiaoi Luo & Wang, sp. nov.). We treat Mimosilpha as the junior synonym of Homalosilpha. The ASR analyses reveal the evolutionary status of genital characteristics in Blattinae s.s., and suggest that the morphology of sclerites L4C, R1H and R1G can be used as diagnostic characters for genera or subfamilies.