A total of 605 vascular plant species, including flowering plants, gymnosperms and ferns, are included in this annotated checklist for Arabuko-Sokoke Forest Reserve in Kilifi County in the Coast Region of Kenya. Out of these 491 are supported by a voucher specimen in the East African herbarium, and 106 are sight records, whereas an additional 8 are cited from the Flora of Tropical East Africa (FTEA). This total represents approximately 9% and 18% respectively of the flora of Kenya and the coastal region (K7 of FTEA). Taxa are distributed in 103 families and 389 genera, the largest families being Leguminosae (Fabaceae) with 62 taxa, Rubiaceae with 53 and Malvaceae with 26. The largest genera include Grewia, Cyperus, Ficus and Ipomoea. For each record a name, a cited specimen or sight record, a short general description, and its known phytogeographic distribution is provided. Globally threatened species are also indicated. The conservation importance of Arabuko-Sokoke is discussed.