In this study, we present phylogenetic data to characterize the relationships among sironids centered in the Balkan region, and use these results to discuss biogeographical aspects of sironid evolution. Analysis of ca. 4.5 kb of sequence data from three nuclear and two mitochondrial genes reveals monophyly of a Balkan clade for which we resurrect the name Cyphophthalmus, considered a junior synonym of Siro for over a century. This clade diversified into several groups, and at least three of them--the duricorius group, the serbicus group, and the minutus group--are well corroborated by the data as monophyletic lineages. The members of the different groups, mostly living in troglobitic environments, have diversified in overlapping geographic regions, with evidence of an eastern origin for the group. Our data also suggest that mitochondrial and nuclear genes are all contributing towards the final resolution of the combined analysis of the data.