Previously reported species that belong to the genus Paraprionospio (Polychaeta: Spionidae) include P. pinnata (Ehlers, 1901), P. inaequibranchia (Caullery, 1914), P. africana (Augener, 1918), P. alata (Moore, 1923), P. tribranchiata Berkeley, 1927, P. treadwelli Hartman, 1951, P. ornata (Berkeley & Berkeley, 1961), P. lamellibranchia Hartman, 1975, P. coora Wilson, 1990, P. tamaii Delgado-Blas, 2004 and P. yokoyamai Delgado-Blas, 2004. Some of these descriptions are confused due to incomplete characterizations. In the present study that aimed to resolve the confusion, (1) Paraprionospio pinnata, P. inaequibranchia, P. africana and P. lamellibranchia are redescribed based on specimens collected from Concepcion, Chile (close to the type locality of Paraprionospio pinnata) and the type specimens (the latter three species), (2) Paraprionospio treadwelli, P. tamaii and P. yokoyamai are synonymized with Paraprionospio alata based on the examination of the type specimens, (3) three new species, Paraprionospio cordifolia sp. nov., P. oceanensis sp. nov. and P. patiens sp. nov. from Japanese coastal waters are described, (4) Paraprionospio coora is recorded from Japan for the first time, (5) 11 diagnostic characters are selected for identifying Paraprionospio species and an identification key to the valid nine species is provided, and (6) phylogenetic relationships between Paraprionospio and other genera in Spionidae and within Paraprionospio are discussed based on the parsimony analysis. c 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 151, 253-284.