Allelopathy is a well known area of active research in ecology. However, its importance in agro-ecology is still underappreciated. This review sets out to address this situation and introduce this new and developing field to a wider research audience and to stimulate new research in it. The review starts with an introduction, followed by discussions of allelochemicals, the role of allelopathy in crop production, Allelopathy related problems in crop production, and Suggestions for future research. It also describes broader research into allelopathy in agriculture and the biosciences, and literature resources on the subject. We hope that it will encourage more scientists to initiate research into this exciting new field.