There are many Ḥadīths in Imamiyeh Shīʿa Ḥadīth sources in which the full names of imams are introduced by the Prophet (PBUH).  These have been directly narrated from the sayings of the Companions (ṣaḥāba), followers, and the twelve imams themselves or from the sayings of the Prophet (PBUH). On the other hand, many historical reports show that not only Muslims but also most Shīʿites were not aware of the names and lineage of their imams. This ignorance has manifested itself in the division of the Shīʿite sect and the creation of sects attributed to imams or their children and it implies that if the Shīʿites knew about the news of the twelve Imams and their complete names and lineage, these divisions would not have occurred. The main question of this article is how the ignorance or lack of knowledge of the Shīʿites about the name and lineage of their imams will be justified despite the existence of that news in the famous Ḥadīth sources of the Imamiyeh. This study seeks to investigate and resolve this conflict. Findings indicate that the number of Ḥadīths with imams’ full names is not as much as it is known in some books and it seems that after the period of occultation, when the number of imams for Shīʿa was determined the subsequent narrations were completed accordingly.