Whistleblowing, defined as the disclosure by organization members of employers’ illegal, immoral or illegitimate practices to persons or organizations that may be able to take action, has been recently regulated in the European Union through the Whistleblower Directive (2019). This allows persons to report breaches of Union Law in a work-related context and member states had to adopt it until the end of 2023. Although many studies focused on the human and situational characteristics of whistleblowing, or on its regulation through administrative and legal procedures, we know very little about its use. Our paper addresses this gap in the literature and aims to explain what makes people working in both private and public organizations to use whistleblowing. It focuses on Romania as a representative case with difficulties in adopting the Directive into its national legislation and a least-likely case where we would expect whistleblowing to occur due to limited experience with such a practice in the past. The analytical framework includes four major categories of explanations: procedural aspects, psychological characteristics (e.g. fear), attitudes towards institutions (e.g. trust), and socio-economic characteristics. The data comes from semi-structured interviews to be conducted in March 2024 with several tens of employees in the public and private sector.