The relationship of human societies to territory and natural resources is being drastically altered by a series of global agreements concerning trade, intellectual property, and the conservation and use of genetic resources. Through a characteristic style of collective appropriation of their tropical ecosystems, Maya societies have created local institutions for governing access to their common resources. However, new mechanisms of global governance require access to Maya biodiversity for world commercial interests. The Chiapas Highland Maya already face this prospect in the International Cooperative Biodiversity Group drug discovery project, which proposes to use Maya medical knowledge to screen plants for potential pharmaceuticals. The ethnobiological focus of the project emphasizes the naturalistic aspects of Maya medicine, primarily the use of herbal remedies. This biological gaze decontextualizes the situated knowledge of Maya healers, ignoring the cultural context in which they create and apply that knowledge. The search for raw materials for the production of universal medical technology results in symbolic violence to the cultural logic of Maya peoples. Only the full recognition of Maya peoples' collective rights to territory and respect for their local common-resource institutions will provide ultimate protection for their cultural and natural patrimony.