Abstract
This paper analyses the changes induced in the political, ethical and epistemological parameters of classical anthropological fieldwork by the world wide emergence of indigenous political movements and related support NGOs. It looks first at the links between post-war development policies and the rise of these indigenous and indigenist organizations. It then introduces a general dis cussion about the relationships between ethno-political struggles, anthropologi cal advocacy, ethnographic research and 'participant observation'. It finally examines the conditions of intellectual independence of an engaged anthro pology and the possible heuristic potentialities of its new field perspective of 'observant participation'.