A wide range of projects are described in the latest Biennial Report of the International Agency for Research on Cancer (IARC), the cancer research branch of the World Health Organization (http://www.iarc.fr/). Most of these projects involve collaborations with scientists in institutes throughout the world, covering topics ranging from descriptive epidemiology and biostatistics, cancer registration and analysis of data on cancer occurrence, to basic research on genetic and molecular aspects of cancer development to pathogenesis and prevention studies. Profusely illustrated, the Report also contains details of the personnel and organization of IARC and its activities, as well as a complete list of over 500 publications and articles authored by its scientists and their collaborators during the biennium.