Directive 2010/63/EU requires the evaluation and authorization of all research projects and training activities involving the use of animals and defines some components and expertise necessary for the evaluation process. Adoption of Directive 2010/63/EU provided an opportunity to harmonize project evaluation processes across Europe, but thus far, member states have used a variety of approaches in the transposition and implementation of Directive 2010/63/EU. The authors discuss and compare the project evaluation systems being implemented in five European Union member states (France, Germany, Spain, the Netherlands and the UK).