Recently there has been a realisation that agriculture, and in particular the viability and sustainability of smallholder farming, can be a key to poverty reduction in developing countries. This article reviews approaches to monitoring and evaluation (M&E) of scientific and technological innovation projects and examines how approaches to M&E can be modified or enhanced to optimise positive impacts on those intended recipients. This article concludes that innovations are most successful when they are accomplished within ‘innovation systems’; that advantage should be taken of opportunities to involve intended recipients of the innovation at early up-stream and mid-stream stages of projects to assess the accuracy and adequacy of theories of change; that the types of tools and methods used in carrying out M&E influence the types of data obtained; and that the cultures of research and development institutions may inhibit reciprocal communications but the development of intermediaries between institutions and farmers could make a useful difference.