During recent fieldwork on Tenerife, several non-native plant species were recorded, some newly documented for the island and others as first records for the Canary Islands. These include fully established species like Brassica fruticulosa Cirillo, Crassula alata (Viv.) A.Berger, and Hydrocotyle sibthorpioides Lam., as well as casual species such as Bacopa monnieri (L.) Wettst. and Nephrolepis biserrata (Sw.) Schott. Many of these species have potential to naturalize or become invasive. Additional notes are provided on Biancaea decapetala (Roth) O.Deg. and Digitaria radicosa (J.Presl) Miq.