Seventeen deep-sea pycnogonid species are reported from the west coast of the temperate United States (California, Oregon, and Washington). The distribution and a diagnosis of each known species is given and four new species, Nymphon aculeatum, Colossendeis peloria, C. spicula, and Hedgpethia nasica, are described and compared with known fauna. All species affinities and relationships with other fauna are discussed and an artificial key to the species of Pallenopsis (Bathypallenopsis) found in the study area is provided. One species, Pallenopsis (B.) oculotuberculosis Hilton, is recorded for only the second time and is illustrated because figures were never published with its original but superficial description.