The fundamental objective of all nuclear safety regulatory bodies is to ensure that activities related to the peaceful use of nuclear energy are carried out in a safe manner within their respective countries. In order to effectively achieve this objective, the nuclear regulatory body requires specific characteristics, one of which is a healthy safety culture. This regulatory guidance report describes five principles that support the safety culture of an effective nuclear regulatory body. These principles concern leadership for safety, individual responsibility and accountability, co-operation and open communication, a holistic approach, and continuous improvement, learning and self-assessment.