In 1989 I became the librarian for the World Rock Art Archive (WRAA), the UNESCO body dedicated to rock art. Under the direction of Emmanuel Anati, then director of WRAA, I participated in the drawing up of the first lisf of fifty prehistoric rock art sites declared a UNESCO World Heritage Site. This work gave me the privileged opportunity to observe the prehistoric rock art from all over the world, and to deepen my research in the field of archaeo-ethnomycology. In this chapter I propose some methodological considerations regarding the archaeoethnomycology of psychoactive mushrooms, with the aim of delimiting the area of scientific research from what I have previously defined as "phanta-ethnomycology" (Samorini, 2001b: 175-9): a literary vein that has produced and continues to produce pretentious theses based on superficial or preconceived observations. This article provides an updated review of two archaeological sites I studied during this period, which are located in the heart of the Sahara Desert and in South India.