Aphelenchoides tabarestanensis n. sp. was isolated during a survey of nematodes associated with bark samples of pine trees (Pinus brutia) in Mazandaran province, northern Iran. The new species is characterised by body length of 656 (580-786) µm (females) and 490 (480-500) µm (males), weakly annulated cuticle, four lines in the lateral field, and an offset lip region. The stylet is 10.5 (10-11) µm long and has small basal swellings. The excretory pore is located at nerve ring level and the hemizonid was not seen. The post-vulval uterine sac is 40.8 (38-43) µm long, the spicules are relatively short (18-19 µm in dorsal limb), and the male tail has the usual three pairs of caudal papillae (2+2+2). The female tail is subcylindrical with two or three minute processes at the tip. The new species belongs to the Group 3 category of Aphelenchoides species and is close to seven known species of the genus, namely: A. asteromucronatus, A. besseyi, A. fujianensis, A. goodeyi, A. ritzemabosi, A. siddiqii, and A. stellatus, but differs by body size, shape of tail mucron, stylet length, size of spicules, and length of post-vulval uterine sac. Phylogenetic analysis based on small subunit (SSU) and partial large subunit (LSU) sequences of rRNA supported the morphological results.