The Scientific Committee of the European Food Safety Authority (EFSA) reviewed the use of risk assessment terminology within its Scientific Panels. An external report, commissioned by EFSA, analysed 219 opinions published by the Scientific Committee and Panels to recommend possible ways of improving the expression and communication of risk and/or uncertainties in the selected opinions. The Scientific Committee concluded that risk assessment terminology is not fully harmonised within EFSA. In part this is caused by sectoral legislation defining specific terminology and international standards for specific fields of risk assessment and thus for specific Panels. The use of defined terminology for risk assessment is driven by three standard-setting organisations, the Codex Alimentarius Commission (CAC) in relation to food safety, the World Organisation for Animal Health (OIE) for animal health and the International Plant Protection Convention (IPPC) for plant health, under the Agreement on the Application of Sanitary and Phytosanitary Measures (SPS Agreement) of the World Trade Organisation (WTO) of which the European Union is a member. Should the major purpose of risk assessment be international trade, the Scientific Committee concludes that particular care must be taken that the principles of CAC, OIE or IPPC are followed strictly. EFSA Scientific Panels should identify which specific approach is most useful in dealing with their individual mandates. The Scientific Committee considered detailed aspects of risk assessment terminology and identified their relevance for EFSA to adopt more harmonised use. These included examining definitions of risk and uncertainty, expressing uncertainty and different levels of risk, the merits of using qualitative and quantitative expressions and the use of glossaries of definitions to improve both the understanding and harmonisation of terminology across EFSA’s scientific opinions. Follow-up action by EFSA is identified to develop appropriate detailed guidance to the Scientific Panels. Recommendations are made to improve the clarity, consistency and where possible the harmonization of risk assessment terminology within and across EFSA’s scientific opinions.