Among the many sayings of the Infallibles (the Prophet and the Imams of Shiˈa), the Hadiths related to Mahdism, as an influential belief among Islamic beliefs, have always been the focus of religious scholars’ attention. Although many of these Hadiths are authentic, however sometimes with some motivations such as gaining religious, political, sectarian, and ethnic interests and benefits, revering oneself, and sometimes with the idea of promoting religion and divine values, some changes have been made in the document and text of some Hadiths.
Although the number of "distorted" Hadiths in comparison with "authentic" narrations are few, this is too much, especially in the basic teachings of Islam, and has led to many harms damages.
To answer the question about the most influential harmful factor affecting the basic teachings of Mahdism, the present article examining a large number of Hadiths, has come to the conclusion that altering the Hadith and creating a transformation in the narrations is the most prominent factor in harming the hadiths about Mahdism.
In this paper, this matter has been re-presented by dealing with the documentary and denotable reviews of some Islamic narrations, which of course have been discussed by some thinkers previously.