Post-marketing safety studies are an important tool for understanding and monitoring the safety profiles of drugs in the clinical setting. Their importance has attracted not only the attention of regulators for reinforcing legislation but also led to recent changes in European Union (EU) regulations; these regulations have influenced the practice of Post-Authorization Safety Study (PASS) by marketing authorization holders. Korea conducts post-marketing surveillance (PMS) studies, but their execution is very different. This editorial reviews the PMS system in Korea in comparison with the recent legislative changes affecting the EU system. Ultimately, it suggests that changes to the PMS system are necessary to obtain quality safety data while maintaining a global standard of operation. Such efforts to refine the system will enhance the credibility of the PMS in Korea and, in due course, produce safety profiles that will be valuable for public health.