The Imperial Woodpecker (Campephilus imperialis) of Mexico—the largest woodpecker in the world—probably became extinct in the late 20th century, without known documentation of the species in life. We describe a recently discovered 16-mm color film of an Imperial Woodpecker taken in 1956 by William L. Rhein. The film documents climbing strides, launches, flights, and foraging of one female Imperial Woodpecker. For perches and foraging the woodpecker used dead or recently dead Durango Pines (Pinus durangensis). Trunks of perch and foraging trees were of the largest diameters available in this tree species. After allowing for possible inaccuracies in the frame speed of the film, we found that the Imperial Woodpecker had slow climbing strides and a fast wingflap rate compared with other woodpeckers. Following landmarks documented during the 1956 expedition, we identified and surveyed the film site in 2010. The site was in coniferous forest in lightly undulating terrain at 2,700–2,900 m elevation. In 1956, the area was oldgrowth forest with abundant large and dead trees. By 2010, the area had been logged multiple times. Interviews with local people indicated that Imperial Woodpeckers had disappeared from the region by 1960 and that they were killed by hunting and perhaps through poisoning instigated by logging interests. Human persecution and the logging of large pines for timber and of dead trees for pulp were likely principal factors in the extinction process of the Imperial Woodpecker.