We investigated the breeding systems of four different Aizoaceae species in Namaqualand, South Africa. Results showed that all four species are xenogamous with negligible amounts of seeds produced when flowers are left to spontaneous self-pollination (autogamy) or self-pollinated. Experiments allowing single visits of pollinators resulted in significantly higher seed numbers in relation to bagged unmanipulated flowers for two species. Pollen–ovule ratios were extremely high and supported the notion that the investigated Aizoaceae species are obligate outcrossers depending on insects as pollen vectors.