Various measures have been taken to minimize risk for individual drug products in the past. It is noteworthy that these measures are now documented and made public as a　“risk minimization plan” with the implementation of the scheme of Risk Management Plan （RMP). Risk minimization activities are conducted with the aim of securing and enhancing patients' safety, and at the same time, it places additional burdens on patients, healthcare practitioners and manufacturers/distributors. In this context, it should be assessed whether the original purpose is achieved. It is the key　for RMP to revise the plan effectively based on the assessment result. Measures to evaluate the effectiveness of risk minimization activities include analysis using medical information databases, questionnaire survey/interview to healthcare practitioner and patients. We may need to conduct prospective/retrospective surveys for some cases. There is no single method to be universally applied to different situations and we have no other way than putting our heads together and moving into action.