Emerging plant pests and diseases are a threat to biodiversity, food security and sustainability. In Europe, recent plant health emergencies include European ash dieback (due to the ascomycete Hymenoscyphus fraxineus), the outbreak of the bacterium Xylella fastidiosa on olive trees in Apulia, Italy and the invasion by the vinegar cherry fly Drosophila suzukii. The main drivers of new plant health threats are increased long-distance plant trade, climate changes and the adoption of new crops (e.g. biofuels). This overview provides an update on available literature on tools and approaches to assess the risk posed by emerging plant health threats in Europe. In the European Union (EU), as well as in other regions, plant health risk assessment (carried out since 2006 by the European Food Safety Authority (EFSA)) is clearly separated from risk management decisions (taken by the European Commission and Council through the Standing Committee on Plant Health). The role of the European and Mediterranean Plant Protection Organization (EPPO) is very important as an independent plant health risk assessment body covering the whole of Europe, not just the EU, thus liaising with neighbouring regions such as the Maghreb, Asia Minor and Russia. The main activities and projects of EPPO and EFSA in the domain of emerging plant health risks are summarized. The ongoing revision of the EU plant health regulations is an opportunity to improve biosecurity in the face of both the massive increase in trade of plant commodities and climate change. However, improving regulations (e.g. integrating new tools from evolutionary ecology and network theory) is not a panacea: there is also the need to increase public awareness and engagement, to facilitate interdisciplinary careers related to plant health, as well as to ensure long-term funding for research on emerging risks to plant health.