White-eyed River Martin Pseudochelidon sirintarae was described in 1968 and there have been no confirmed sightings since the 1970s. It is known only from Bueng Boraphet in central Thailand. Here, we compile the most comprehensive summary of museum specimens, photographic records (including two previously unpublished images) and sightings for this poorly known species. Specimens are held mainly in the Thailand Natural History Museum near Bangkok, with others at the Natural History Museum (Tring), American Museum of Natural History (New York) and National Museum of Natural History, Smithsonian Institution (Washington, DC). At least three other mounts exist, all in Thailand, some of which may be composites from captive birds collected in the early 1970s. Photographs unearthed at Tring, and in unpublished reports, show birds that differ from the four previously known images and may represent individuals that are now museum specimens. With no confirmed sightings for more than 40 years, despite reasonable search effort (especially increasing citizen science data), it is very likely that White-eyed River Martin is now extinct.