Hajj and ‘Umra were considered two independent rituals being performed in two different periods of a year (‘Umra in Rajab and Hajj in Hajj months) in the Ignorance Era. In the Islamic period these two rituals were performed in the same way until the10 th year (A.H.) when the holy Prophet commanded people to perform Hajj and ‘Umra simultaneously during his last pilgrimage and emphasized their simultaneity forever. Despite establishment of that juristic precept in both Shi‘a and Sunni hadiths, there are some disputes in Sunni hadiths concerning the very legitimacy of ‘Umra al-Tamattu‘ and its subsistence or abolition. While judging those disputes the present essay would deal with that subject in a comparative manner.