The Endangered Mangshan pit viper Protobothrops mangshanensis is endemic to the Nanling Mountain Range of China. It has been targeted for exploitation to satisfy the international pet trade and zoological collections since it was described. Long-term intensive exploitation and habitat destruction have resulted in drastic reductions in wild populations, pushing this rare species towards extinction. Since 1990 only limited investigations have been conducted and the most optimistic estimation of the population size was 300–500 individuals, in 2000. Since then, however, there have been no updates on the population status of this snake in the wild. To provide baseline data for effective conservation of this species we conducted a study of its status and distribution, during 2007–2010. Only eight individuals were found during fieldwork and we documented the illegal harvesting of >30. The total population of the species was estimated to be 462, occupying c. 105 km2 in the Nanling Mountain Range. The black market price of a Mangshan pit viper is currently >USD 1,000 kg−1 and illegal trade has led to over-harvesting, which is the greatest threat to the species. Our study indicates that protected areas cannot effectively protect this pit viper if the trade in this species cannot be controlled. Based on the results of our study we present five recommendations for conservation of the species.