We investigated the colonization of the Indian Ocean archipelago of Socotra through phylogenetic analysis of Aerva (Amaranthaceae) based on nuclear and plastid DNA sequence data. The biogeographic history of the genus was tracked using ancestral area reconstructions and molecular dating. Three independent colonization lineages from the Eritreo-Arabian subregion of the Sudano-Zambesian Region were revealed: one endemic clade comprising Aerva revoluta/A. microphylla and once within A. lanata and A. javanica. Our results provide further support for the dominance of Eritreo-Arabian affinities in the flora of Socotra, in contrast to more rare affinities to Madagascar, the Mascarenes, southern Africa, and tropical Asia. Our data point towards colonization via dispersal, rather than a vicariance origin of the island elements. The overall biogeographic patterns of Aerva show only limited concordance with other taxonomic groups distributed on Indian Ocean islands.