The article analyzes anti-religious propaganda in the early 1920s in the Buryat-Mongol Autonomous Soviet Socialist Republic on the example of the magazine Erdem ba Shazhan [Science and Religion]. An important component of the state policy in the antireligious struggle in the republic was the Regional Union of Atheists, created in Verkhneudinsk on December 2, 1926. The publication of Erdem ba Shazhan in the Mongolian script was aimed at covering the gap of specialized literature on anti-religious propaganda. While analyzing issues of the magazine stored in the Center of Oriental Manuscripts and Xylographs of the Institute for Mongolian, Buddhist and Tibetan Studies of the Siberian Branch of the Russian Academy of Sciences, research methods of historical science were used. The source study method has revealed the significance of the magazine as a source for studying atheistic propaganda and introducing a new socialist ideology in Buryat society. Erdem ba Shazhan was a methodological guide for a wide network of circles of the League of Militant Atheists. The magazine described the anti-religious events held in the republic, discredited false religious postulates, and propagandized the new Soviet style of life. For instance, the magazine published scientific disputes with lamas about the essence of religion. The analysis of the contents of Erdem ba Shazhan shows that educational issues were aimed at the broad promotion of the new life and eradication of religious remnants occupied more than a half of its volume. The magazine had no thematic sections, but it is possible to identify several main headings: propaganda and educational materials, popular scientific articles, short news, literary life. The “short news” part presented items on the activities of not only the Union of Atheists, but also of the first scientific organization—Buruchkom. The history of overcoming religiousness and inculcating the new ideology found reflection in the works of fiction the magazine published. Young writers, scientists, and educators (Kh. Namsaraev, Ts. Don, D. Madason) collaborated with Erdem ba Shazhan. The magazine also contained visual materials: photos, drawings, caricatures. It is worth noting the original design of the magazine cover made by Ts. Sampilov. Along with other publications in the Mongolian script, Erdem ba Shazhan promoted the development of atheistic education. The magazine illustrated the most diverse aspects of the life of the Buryat population with an emphasis on the scientific nature of events. Thus, the publication of the magazine Erdem ba Shazhan had a significant impact on the development of the atheistic movement in the republic, along with more accessible forms of printed propaganda in the form of posters and other visual means, such as cinema and theater. In general, this magazine compensated for the lack of specialized literature in the Buryat language, being the only methodological guide for a network of atheist cells in rural areas.