Ornithologists studying the wetland avifauna of the island of Hawaii during the late 1800s reported two endemic species (Hawaiian Rail Porzana sandwichensis and Hawaiian Duck Anas wyvilliana), three endemic subspecies (American [Hawaiian] Coot Fulica americana alai, Black-necked [Hawaiian] Stilt Himantopus mexicanus knudseni, and Common [Hawaiian] Moorhen Gallinula chloropus sandvicensis), and one indigenous species (Black-crowned Night-Heron Nycticorax nycticorax hoactli) (Wilson and Evans 1890–1899, Rothschild 1893–1900, Henshaw 1902, Perkins 1903). The rail is now extinct. The moorhen, although present on other islands, has been extirpated from Hawaii. The coot, moorhen and duck are classified as endangered by the State of Hawaii and the Federal government (USFWS 1983). One other endangered endemic water bird, the stilt, was apparently absent from the island from 1896 to as recently as the early 1960s (Walker 1962, Banko 1979, Paton and Scott 1985). Research is currently being conducted on the Hawaiian Duck by the Hawaiian Division of Forestry and Wildlife (HDFW), as information on this species is limited (Jon Giffin pers. comm.). Surveys of the wetlands of Hawaii conducted over the past 20 years by the HDFW have provided baseline data on the population trends of the coot and stilt (unpubl. data on file, Dept. of Land and Natural Resources, HDFW). The purpose of this paper is to summarize existing knowledge of these two endemic water birds on the island of Hawaii.