The European Partnership for Alternative Approaches to Animal Testing (EPAA) convened a workshop Knowledge sharing to facilitate regulatory decision-making. Fifty invited participants from the European Commission, national and European agencies and bodies, different industry sectors (chemicals, cosmetics, fragrances, pharmaceuticals, vaccines), and animal protection organizations attended the workshop. Four case studies exemplarily revealed which procedures are in place to obtain regulatory acceptance of new test methods in different sectors. Breakout groups discussed the status quo identifying the following facilitators for regulatory acceptance of alternatives to animal testing: Networking and communication (including cross-sector collaboration, international cooperation and harmonization); involvement of regulatory agencies from the initial stages of test method development on; certainty on prerequisites for test method acceptance including the establishment of specific criteria for regulatory acceptance. Data sharing and intellectual property issues affect many aspects of test method development, validation and regulatory acceptance. In principle, all activities should address replacement, reduction and refinement methods (albeit animal testing is generally prohibited in the cosmetics sector). Provision of financial resources and education support all activities aiming at facilitating the acceptance and use of alternatives to animal testing. Overall, workshop participants recommended building confidence in new methodologies by applying and gaining experience with them.