This book is not a text book, but a very useful and unique reference book entitled Radiological Protection and Safety - A Practitioner's Guide designed to guide people, who are interested in radiological protection, Health Physicists (HPs), Radiological Safety Officers (RSOs) and Medical Physicists, operators, regulators, or anyone responsible for radiological protection of the workers, the patients, the public and the environment. Radiation protection is a multi-disciplinary subject. The concepts of radiological protection, radiation protection standards, regulations, types of radiation sources and the applications are continually changing over time. There are newer challenges to practitioners and facility management to ensure radiological protection and safety of the personnel and the environment, during normal operations and in emergency situations. There is a need to update their overall knowledge while developing processes/technologies in public domain on peaceful applications in medicine, research, industry and agriculture. Optimization of protection is the key to keep the exposures low. Public safety is of prime concern. This reference guide is written by a practitioner who has decades of experience in radiological safety and regulation. The guide is organized in about 300 pages and in 18 chapters, is intended to serve the purpose of finding all radiological safety related topics in one place, including the biological effects of radiation exposure, along with the recent references. It also covers the updated status on issues and topics of concern in natural radiation sources, nuclear fuel cycle operations and in the wide variety of applications of radiation and radioisotopes. Nuclear and Radiological emergency is considered important and is separately covered in the chapter on radiological protection in emergency exposure situations. Decades of operational radiation protection experience gained is transformed selectively to create knowledge to educate and train all those who are involved in the specialized topic of radiation protection, which is not taught in all colleges. The gap in the knowledge is expected to be filled to a great extent by this this reference book. It is invaluable and for keeps. Read this book to learn how the radiation hazards control measures like monitoring of the individuals, the workplaces and the environment demonstrate that the occupational exposures are low, and the environmental impact is negligible during normal operations. I dedicate this book to all the stakeholders in ionizing radiation utilization, including the radiation protection community.