The large increase in the size of the international scientific community, coupled with the desire to ensure the appropriate and efficient use of the substantial funding devoted to supporting scientific research, have understandably led to an increased emphasis on accountability and on the evaluation of both researchers, research activities and research projects (including recruitment, as well as the evaluation of grants and prizes). Given that there is a large diversity of procedures currently used in evaluations which have accumulated over time, it is now necessary to provide some guidelines for best practice in the evaluation of scientific research. Peer review, adhering to strict standards, is widely accepted as by far the best method for research evaluation. In this context, the present statement focuses on the evaluation of individual researchers.