"Regulatory Science Meets Epidemiology." is this year's theme for the 26th Annual Meeting of the Japanese Society of Pharmaceutical Epidemiology. Pharmacoepidemiology is the discipline aiming to ensure rational use of medicines and medical devices and consequently to bring healthier life and better QoL to patients, which is based on epidemiological methodologies as science base and international/local pharmaceutical laws/regulations as the foundation for practical applications. As the statutory/regulatory system governing healthcare, and technologies/methodologies used for evaluating drug safety/efficacy have been evolving at a breakneck speed recently, we are witnessing that the span of research area and data sources used in pharmacoepidemiology is greatly affected and enlarged. This annual meeting hopes to develop and share discussions on the use and mission of drug epidemiology in the development life cycle of pharmaceuticals and medical devices, including from the perspective of regulatory science.