A new species from the Annamite mountain range of central Vietnam Hoya thuathienhuensis is here described and illustrated. Its flowers bear similarity with Hoya lockii a taxon recently described from the same area with which it shares the reflexed corolla and the thin coriaceous laves. Hoya lockii is an epiphytic shrub whereas H. thuathienhuensis is a strong climbing liana. We also report the noteworthy extension into southern Vietnam of Hoya graveolens a taxon previously considered to be endemic of Thailand.