The encyclopedic dictionary offered to the attention of readers is the first manual in Russian, in which an attempt was made to explain most of the basic concepts and terms that are used in the Islamic tradition. In addition, this work contains quite detailed information about various legal and doctrinal schools in Islam, the fundamentals of Islamic doctrine, the doctrine of monotheism, and contains a large amount of material on various Muslim sects. It also contains biographical information about the most famous companions of the Prophet Muhammad and their followers, about famous jurists, thinkers, interpreters of the Koran, and kalamists. Biographies of many members of the family of the Prophet Muhammad are also given. There is detailed information on Islamic primary sources - the Koran and Sunnah, their history and methods of interpretation. Most of these topics are published in Russian-language Islamic literature for the first time. All topics and terms in the encyclopedic dictionary are presented in alphabetical order. In addition, the book is supplemented with a thematic section. In this section, which appears at the end of the dictionary, all terms are grouped by topic. Readers just need to find a topic that interests them and read the list of terms that are explained in the book in alphabetical order. Thus, this encyclopedic dictionary is designed in such a way that it becomes at the same time a short reference guide for any person who wishes to become acquainted with various aspects of Islam and Muslim civilization. This structure of the book is also new and is used for the first time in Russian-language Islamic studies literature.