The cao-vit crested gibbon (Nomascus nasutus) is one of the world’s most endangered primate species, with one single protected forest patch in the border area between Cao Bang province (Vietnam) and Guangxi province (China) supporting the last known population. No other locality is known to support a population of this species, however, some gibbons are rumoured to have survived in Kim Hy Nature Reserve of Bac Kan province (northeastern Vietnam). Although several previous surveys in Kim Hy failed to find direct evidence for the continued occurrence of gibbons there, each provided interview information indicating that Kim Hy still supported a few gibbons. In order to resolve the contradiction, we conducted a two-week survey in Kim Hy in June 2009. We recorded intrusion of agriculture in the periphery of the nature reserve, massive logging going on mostly, but not exclusively, in the periphery of the reserve, and hunting and gold mining in all areas including the corezone of the reserve.