Families and next of kin are important partners in patient safety. In two Norwegian counties, next of kin who had lost a family member due to an adverse event participated in in-person meetings with inspectors as part of the regulatory investigation. This study explored the experiences and perspectives of the next of kin (Part 1) and regulatory inspectors (Part 2) involved in this new approach to next-of-kin involvement in regulatory investigations. Despite being an emotionally challenging process, next of kin viewed participation in the regulatory investigation as a positive experience and believed that their contributions improved the investigation process.