Geranium subsect. Mediterranea (Geraniaceae) consists of ten species. The highest diversity of the group is located in the Caucasus and neighbouring areas of Turkey and Iran, with five endemic species. Other species reach western Europe and northwestern Africa. In contrast to the current literature, we consider G. montanum and G. ibericum subsp. jubatum to be synonyms of G. ibericum. A univariate morphometric study revealed some valuable quantitative characters useful for the identification of these species. Micromorphological features of pollen, stigmas, seeds, and mericarps were investigated by SEM. A new key is provided, as well as new and detailed descriptions. Geranium kurdicum is here illustrated for the first time. Eleven lectotypes are designated, and distribution maps are presented. Maximum parsimony and Bayesian analyses of chloroplastic trnL-trnF and ribosomal nuclear ITS regions suggest that sect. Mediterranea is monophyletic. Two clades are recovered, one including the annual species and other with the perennials, in which G. tuberosum (subsect. Tuberosa) emerges within a paraphyletic subsect. Mediterranea.