Résumé : A catalogue of the flowering plants of the islands of São Tomé and Príncipe (Gulf of Guinea) is presented. Flowering plant diversity figures are updated to: 135 families (20 introduced), 624 genera (172 introduced), 1 104 species (301 introduced) plus 15 additional infraspecific taxa. At present 119 taxa (107 species and 12 infraspecific taxa) are known to be endemic to the two islands. The catalogue includes accepted names, synonyms used in recent literature, common names, voucher specimens and information on habit and habitat and on plant uses, particularly medicinally.