Sheikh Abdulhosein Tehrani (Sheikh Al-arāghin) is considered as one of the greatest theologians in Tehran from Mohammad Shah Qajar till Naser Al-din Shah Qajar. In the first part of this article, the author is going to give a detailed account of Sheikh’s biography, his professors, students, publications, and services. In the second part, he provides a report of Mesbāh Al-nejāt fi Asrār Al-salāt and explains some of its author’s characteristics. Finally he examines the problem that whether the author of the mentioned book is Sheikh Abdulhosein Tehrāni or a contemporary author with the same name.