The article examines the peculiarities of theoretical approaches to understanding the category of «abuse of law» in the countries of the Anglo-American legal family, primarily in Great Britain and the United States. In particular, by using a set of philosophical and worldview, general scientific, special scientific methods (primarily, comparative legal, historical legal, normative, functional) and principles of scientific knowledge: the evolution of theoretical ideas about the abuse of law, their consolidation in legislation and practical implementation in individual states of the Anglo-American legal family; the peculiarities of the legal terminology used in the legislation and judicial practice of Great Britain and the USA to determine the abuse of the right are revealed; the characteristic features and general trends of the theoretical understanding and legislative consolidation of the category of «abuse of law» in the specified states have been established. It is argued that the principle of good faith is inherent in the entire legal system of Great Britain as a whole and is reflected in its individual provisions, and the duty to establish the facts about the presence or absence of abuse of the law corresponds to judicial or other competent authorities. It has been established that the doctrine of good faith is important in US judicial practice, but there is no description of the criteria of good faith in US law, their definition is left to the discretion of the court. It is proved that both English and American legislators do not provide a clear definition of the term ‘abuse of law’ in the provisions of legislation. The content of this concept is defined and disclosed in judicial practice and legal doctrine, which are closely interrelated and are based on the assessment of such actions from the standpoint of reasonableness, good faith and fairness. Depending on the branch of law and the legal system of the state, abuse of law is most often understood as damage or loss. Damage is the destruction or diminution of material goods. Losses are understood as real losses and lost profits. It is concluded that despite the fact that the problem of abuse has not been comprehensively resolved, in practice the judicial system of the United Kingdom and the United States is quite effective in combating manifestations of abuse of law.