This monograph is an outcome of research completed within the Visegrad Grant “Workplace Whistleblower Protection in the V4 Countries, France and Slovenia” – WhistlePro (2020–2021), financed from the International Visegrad Fund. The project aims to contribute to the improvement of the legal framework in the Visegrad countries concerning the protection of workplace whistleblowers and, indirectly, to the change of workers’ attitudes towards whistleblowing. Contributions prepared by legal experts from various countries and universities concern matters of universal importance such as freedom of expression relative to whistleblowing, personal scope of the EU Whistleblower Protection Directive (2019/1937) or personal data protection. They also discuss the legal situation concerning whistleblower protection in the Visegrad countries, France and Slovenia and present recommendations for changes in the respective countries. The monograph culminates with a summary of proposals for the improvement of the legal situation of persons disclosing breaches of law in the work-related context. Given its topicality and in-depth analysis of legal problems related to adequate whistleblower protection, the book may be of interest to academics, practitioners, social partners, non-governmental organisations (NGOs) and policy makers in the process of the EU Whistleblower Protection Directive transposition in Member States. Dagmara Skupień