Since the discovery of X-rays, medical imaging has been one of its most important applications. In the course of years, understanding of the potentially harmful effects of radiation on tissue has substantially increased as a result of experience and scientific studies. This has led to the International Commission on Radiological Protection (ICRP), the organisation that is now regarded as the most authoritative in the field of information on radiation and radiation protection. In most countries the law governing radiation is based on the 3 principles of the ICRP: justification, ALARA and dosage limits. For the Dutch situation, these are the Nuclear Energy Act (Kernenergiewet) and the Radiation Protection Decree (Besluit stralingsbescherming). The Practice Guidelines on Radiology are available for the practical implementation of the regulations. By working according to the Practice Guidelines, the dentist satisfies the legal regulations, but, more importantly, he can apply X-ray diagnostics in a manner that is safe for him, the dental team, the patients and all other visitors of the practice.