We are very pleased to have the reflections of Orlando Fals Borda, eminent action researcher and politician from Columbia, on the start up and diffusion of participatory action research. Professor Fals Borda writes from the vantage of his personal involvement in PAR over the last 30 years. He recalls points of departure, the pioneers, theoretical advances and institutional assimilation, as well as challenges and obstacles in knowledge formation. Pertinent current sources and schools of thought are pointed out. The need for related social movements for promoting significant change in societies in northern and southern countries is stressed, with recommendations for the productive and worthwhile role of scientists committed to PAR endeavours.