In Shiite narrations, the inevitable signs of the uprising of Imam Mahdi (a. s. ) have been dealt with, and it is necessary to determine their true number and examples. The present article deals with this issue, and, following an examination of the Shiite narrations, it provides a clear picture of the inevitable signs of the uprising of Imam Mahdi (a. s. ). After analyzing 17 signs cited in the narrations, it was concluded that, in Shiite narrative sources and according to the specific criteria for distinguishing inevitable signs from the uncertain ones, only the following four signs are reliable: 1) the uprising of al-Sufyani, 2) Khasf al-Baydaʾ (an incident in which the Earth will swallow the land al-Bayda), 3) the murder of zakiyyah (pure) soul and 4) the Heavenly call. However, on the basis of the same narrations and criteria, the inevitability of 1) Yamani, 2) Khasfas apart from Khasf al-Baydaʾ , 3) Dajjal, 4) the Bani al-Abbas dispute, 4) the descent of Jesus (a. s. ), 5) a cry in the month of Ramadan, 6) the outflow of fire from Aden, 7) the appearance of a hand in the sky, 8) smoke, 9) the rising of the sun from the west and 10) the Ahjar al-Zayt incident has been seriously criticized. Some of them do not have a considerable narrative evidence, and some others are signs of the Day of Judgment, and they have been mistakenly or negligently taken for the signs of the reappearance of Imam Mahdi (a. s. ).