Tomato yellow leaf curl virus was introduced in Réunion island in 1997 and has become the most important viral pathogen affecting tomato crops in this area. In Réunion island, the vector Bemisia tabaci is continuously present on a large list of wild and cultivated plant species. In order to establish control measures, it is important to know the role of weeds in the conservation of the virus. About 258 specimens belonging to 37 weeds species and 19 botanical families were collected from four fields planted with tomatoes or beans showing TYLCV symptoms. Both serological (ELISA) and molecular (dot-blot, Tissue Print Hybridization, PCR) methods were assayed on each sample in order to detect TYLCV or another begomovirus. TYLCV-[RE] (confirmed by DNA sequence comparisons) was detected mainly in six weeds families: Amaranthaceae, Commelinaceae, Convolvulaceae, Euphorbiaceae, Malvaceae and Solanaceae. The three first families had never been described as natural hosts for the TYLCV and any begomoviruses. The role of these weeds as potential sources of TYLCV will be further studied via experimental transmission tests.