This is a scholarly study of a copy of the Holy Quran which is located in Cairo and attributed to the time of Caliph Othman. Among the copies dating from that period, this one is known as the “Cairo Mushaf ”. It is preserved presently in the Central Library of Islamic Manuscripts affiliated to the Ministry of Awqaf of Egypt. The study compares it to the other copies of the same period located in different cities, namely the Topkapı copy, the Turkish and Islamic Arts Museum copy, the Tashkent copy (preserved at the Khazrati Imam Mosque in Tashkent, Uzbekistan) and the copy of the Great Mosque of Sana’a. Abu Dhabi Authority for Culture and Heritage provided financial contributions for the printing of the book.