The dataset includes benthic infaunal abundance data derived from the EPA National Coastal Assessment and Southern California Coastal Water Research Program Bight ’03 studies west coast shelf assessment studies in 2003, that were combined to form a composite data matrix of 255 stations by 1470 taxa. NCA successfully sampled 146 stations from Cape Flattery, WA, to Pt. Conception, CA in the period June 1 - 26, 2003 (NOAA Cruise AR-03-01-NC), with data from one additional NCA station off Santa Catalina Island provided to the study by SCCWRP. Fifty stations each within Washington and Oregon and 47 stations from California were successfully sampled. An additional 110 stations, located within the Channel Islands National Marine Sanctuary (27) and throughout the Southern California Bight (83, Pt. Conception, CA to the Mexican border), were successfully sampled for some or all of the NCA parameters within the target depth range by participants in the Bight ’03 survey (Ranasinghe et al. 2007). Benthic macrofaunal samples were obtained from these 257 stations, but two stations (OR03-0010, CA03-4339) failed quality assurance checks, and the final total included benthic samples from 255 stations. This dataset is associated with the following publication: Henkel, S., and W. Nelson. Assessment of spatial patterns in benthic macrofauna of the U.S. west coast continental shelf. Journal of Biogeography. Blackwell Publishing, Malden, MA, USA, 45(12): 2701-2717, (2018).