Summary: Bursaphelenchus vietnamensis n. sp., isolated from acacia wood chips from Vietnam is described. It is characterised by a slim body (a = 29-43), lateral field with four lines, excretory pore anterior to metacorpus, female vulva at 76% of total body length, a distinct vulval flap in lateral view, post-uterine branch well developed, extending for 3/4 of the vulva to anus distance, tail conical, smoothly tapering, 4.3-5.5 anal body diam. long, slightly ventral curved, with a pointed or finely rounded terminus, male spicules with weakly developed rostrum and condylus and cross-striped in their central part, a single precloacal papilla and three pairs of ventro-sublateral papillae present. It belongs to the africanus group of genus Bursaphelenchus and is most similar to B. paraburgeri . Detailed phylogenetic analysis based on the partial 18S, ITS and 28S D2-D3 region confirmed the status of this nematode as a new species.