This article introduces aspects of the regulatory writing profession in China and Japan. Although regulatory medical writing is at an early stage of development in China, the ever-growing research and development activities in this country have led to an increasing need for regulatory medical writing. In Japan, the Ministry of Health, Labour, and Welfare has made significant changes in recent years in order to address a downward trend in new drug applications due to the lengthy and expensive processes for clinical studies and approvals, and to shorten the lag in the availability of drugs compared to other developed countries. The changes introduced by the Ministry of Health, Labour, and Welfare include a more simplified and efficient approach to clinical studies while improving infrastructure and introducing global standards, such as the International Conference on Harmonisation/Good Clinical Practice. Accordingly, the increased demand for clinical studies has led to an increasing need for medical writing support for regulatory documents in Japan. Both China and Japan have their own regulatory authorities equivalent to the United States Food and Drug Administration, but there are also marked differences leading to challenges and opportunities for regulatory writing.