Due to new, previously unknown, properties attributed to engineered nanoparticles many new products are introduced in the agro-food area. Nanotechnologies cover many aspects, such as disease treatment, food security, new materials for pathogen detection, packaging materials and delivery systems. As with most new and evolving technologies, potential benefits are emphasized, while little is known on safety of the application of nanotechnologies in the agro-food sector. This review gives an overview of scientific issues that need to be addressed with priority in order to improve the risk assessment for nanoparticles in food. The following research topics are considered to contribute pivotally to risk assessment of nanotechnologies and nanoparticles in food products. • Set a definition for NPs to facilitate regulatory discussions, prioritization of research and exchange of study results. • Develop analytical tools for the characterization of nanoparticles in complex biological matrices like food. • Establish relevant dose metrics for nanoparticles used for both interpretation of scientific studies as well as regulatory frameworks. • Search for deviant behavior (kinetics) and novel effects (toxicity) of nanoparticles and assess the validity of currently used test systems following oral exposure. • Estimate the consumer exposure to nanoparticles.