The main issue of the present study is how Heinz Halm introduced Nasiriyah and to what extent it is in line with the main sources. This article uses a descriptive-analytical method and a historical approach to explain and critique Heinz Halm's views on the Nasiriyah as a Shiite sect. Halm expressed his views on this sect mostly in the book of Ghannusian and the Nasiriyah article in the Leiden Encyclopedia of Islam (EI2), which is the main focus of this study. While trying to correctly explain the history of Nasiriyah based on Islamic sources and their connection with the exaggerators of early Islam, Halm attempted to introduce prominent figures of the Nasiriyah sect, its teachings, rituals and festivals based on Batiniyya thought, and interpreted this as a mystical nature for Nasiriyah, which needs reflection. Considering the importance of the Encyclopedia of Islam (EI2), which is an important source and reference for studies in scientific centers, as well as the scientific authority of authors of encyclopedia Shiite articles, research-basedness, and new achievements of studies, it seems necessary to examine their views in order to achieve strengths and weaknesses, modify them, and more appropriately introduce Shiite sects, and this research is also responsible for part of this.