Iurus populations from the Aegean area are studied, including the Greek islands of Crete, Karpathos, Kythira, Rhodes, and Samos. A new genus, Protoiurus gen. nov., and two new species, Protoiurus rhodiensis sp. nov. and P. stathiae sp. nov., are described. The two genera, Iurus and Protoiurus, are diagnosed by their hemispermatophore structure; a cladistic analysis based on this structure is presented. Genus Iurus Thorell, 1876 includes three species: I. dekanum, I. dufoureius, and I. kinzelbachi; genus Protoiurus includes five species: P. asiaticus comb. nov., P. kadleci comb. nov., P. kraepelini comb. nov., P. rhodiensis sp. nov., and P. stathiae sp. nov. The type specimen of Chaerilomma dekanum Roewer, 1943 has been studied and determined to be a valid species Iurus dekanum (Roewer, 1943) representing the population from Crete. New diagnoses for subfamilies Calchinae (genus Calchas) and Iurinae (genera Iurus and Protoiurus) are provided as well as keys to the species of Iurus and Protoiurus.