This paper explores ways in which experiential learning theories, in particular transformative learning theory, can inform farmer participatory research and extension (PR&E). I identify and discuss three key elements of experiential learning theory – second-order experiences, reflection, and dialogue – that are particularly pertinent to PR&E practice. I then turn to one experiential learning theorist – Mezirow, and examine his theory of transformative learning to assess how it may inform the PR&E process. I outline the basic components and stages of (...) transformative learning and summarize the main criticisms of the theory. Following this, parallels are drawn between transformative learning and what actually takes place in PR&E, and examples are given of the ways in which scientists and rural people may undergo transformative learning through the PR&E process. Ways in which transformative learning can be encouraged within the PR&E context are discussed. I conclude that Mezirow’s work can provide PR&E practitioners and theorists with additional insights into how adults learn and especially how they – researchers, extensionists and rural people – can transform their ways of thinking to accommodate a shift from conventional research and extension to PR&E. (shrink)