A major task of the Grouse Specialist Group is to compile an IUCN/SSC Action Plan to assess threats and propose conservation actions for all grouse species worldwide. This paper provides an overview to the conservation status of and major threats to grouse based on information collected during the preparation of the Grouse Action Plan. Three species, Caucasian black grouse Tetrao mlokosiewiczi, Chinese grouse Bonasa sewerzowi and Siberian grouse Falcipennis falcipennis, are listed as globally near-threatened or data deficient, one newly-recognised species, Gunnison sage grouse Centrocercus minimus, is listed as globally endangered and two subspecies, Attwater's prairie chicken Tympanuchus cupido attwateri and Cantabrian capercaillie Tetrao urogallus cantabricus, qualify to be listed as globally threatened according to IUCN criteria. At a national level, 14 of the 18 species are red-listed in at least one country. Populations at the southern edge of a species' range and in densely populated regions are most often red-listed. Based on questionnaire results from 38 countries, habitat degradation, loss and fragmentation due to human land use activities are the major threats to grouse viability. Exploitation, predation and human disturbance were regionally felt to be critical. Major threats and their causes are reviewed based on questionnaire results and the literature. Integrating habitat preservation and human land use practices is concluded to be the major challenge to grouse conservationists worldwide.