This revised, fifth edition of Practical Radiation Protection pro¬vides insight into the hazards of applying ionising radiation and the practical methods to control these hazards. The book is a translation of the ninth edition of Praktische Stralingshygiëne (2022), with some corrections to the Dutch text. The book is intended for anyone who works with open sources, sealed sources or X-ray equipment. It is aimed at radiation protection officers (RPOs) working with: • industrial radiography equipment; • measurement and control applications; • dispersible radioactive substances at C and D level; • medical applications. It fulfils the course requirements for the RPOs in these sectors, as laid down in Appendix 5.2 Part A of the Regulations on basic safety standards for radiation protection. The necessary depth of knowledge differs per sector; throughout the training the lecturer will guide you on this. In addition the book may be used for: • radiation workers in these settings; • radiation protection experts; • anyone with an interest in this issue (managers, policy makers, journalists, etc.). New to the fifth English edition is that—in addition to the basic knowledge—in-depth paragraphs have been included; these are not part of the course requirements. An extensive literature list has also been added. The book is now entirely in full colour. Chapter 2 gives an updated overview of the applications of ionis¬ing radiation in the Netherlands. New in this chapter is the treat¬ment of the decay chain of uranium and radon. Chapter 3, on interaction of radiation with matter and shielding of radiation, gives some more information on high-energy elec¬trons and presents and discusses half-value layers in the easy-to-apply unit cm.