Archaeological and palaeontological excavations were conducted as part of the Pitcairn Islands Scientific Expedition (January 1991 to March 1992). In this preliminary analysis of the subfossil bird bones from Henderson Island (24022( S, 12S018( E) we identified 29 taxa, which were divided into five groups: (1) four endemic extinctions, (2) five local extinctions, (3) a minimum of 12 breeding residents, (4) three non-breeding migrants, and (5) five birds of uncertain status. Over half of the landbird species known from Henderson Island are listed here for the first time, including one new genus and at least three new species. New listings for Henderson Island include: Henderson Archaic Pigeon (Columbidae new genus), Henderson Ducula Pigeon (Ducula new species), Henderson Ground-Dove (Gallicolumba new species), Henderson Sandpiper (Prosobonia new species), Royal Albatross, Little/Audubon’s Shearwater, Bulwer’s Petrel, Black-winged Petrel, Sooty Tern, cuckoo (Eudynamys sp.), and a swallow (Hirundo sp.). Most of the bird bones collected were associated with prehistoric Polynesian occupation sites dating from ca. AD 1000 to 1600. Humans may have caused the extinction of at least four of the eight endemic landbirds, which equates with similar extinction rates on other Pacific islands.