The objectives of the review were to investigate the legal and sociological basis of justification in society in order to fully assess its relevance to radiation protection. The difference between the justification of practices as distinct from the justification of reasons for the justification of individual activities within a practice and the relevance of cost-benefit analysis to this process are key elements. Justification of practices as a principle of radiation protection is automatically enshrined within the appropriate legislation once it has been enacted. However, the justification of reasons for justification of activities within a practice are subject to many sociological factors, which are often conflicting and indeterminate and can be subject to political, economic and environmental factors that may change over time. This applies especially to new developments where the primary reason for justification is based upon potential but possibly ill-defined future benefits. The primary mechanism whereby society develops a collective consensus on the justification of practices lies within a legal framework. This represents the mechanism by which society defines the accepted standards that must be applied for acceptance of a practice. The justification of reasons for justifying activities that form part of a practice has largely been ignored within the framework of radiation protection. The employment of justification of practices as a fundamental principle of radiation protection should be eliminated since it is already enshrined within the legal framework applicable to applications of ionising radiation. Justification of reasons for pursuing new or modified practices is based upon their perceived benefits to society, which underpins most developments in society. Copyright © 2020 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.