Understanding the various aspects of the history of the pre-Islamic Arabs, including its cultural aspects, helps historians understand the context in which Islam emerged, and this in turn helps them better understand the events of Islamic history, including the established rules of Islam. Analyzing the pre-Islamic Arabs' attitude towards the concept of death and, consequently, the traditions they followed to mourn the dead, is one of the best windows for studying pre-Islamic culture, which reveals the importance of issuing some hadiths about types of mourning. The main goal of this research was to use a descriptive-analytical method to gain insight into the beliefs of the people of the pre-Islamic era regarding death and their mourning methods, to examine the hadiths narrated from the Messenger of God in Sunni and Shiite sources, and to bring in the opinions of scholars of different schools and their common and divergent opinions. The main goal of this research was to clarify the boundary between the mourning accepted in Islam, which is praiseworthy, and the reprehensible mourning methods that have not been approved by Islam, such as the pre-Islamic tradition of al-Niyaha. It also introduced the characteristics and examples of the mourning methods of the present era, which have the color and flavor of pre-Islamic mourning.