[1] The mosque is situated on what was once the main avenue and ceremonial heart of Cairo, known today as al-Mu'izz Street, in the immediate neighborhood of the former Fatimid caliphal palaces.

The mosque is an important monument of Fatimid architecture and of historic Cairo due to the exceptional decoration of its exterior façade and the innovative design of its floor plan.

[4]: 37 He had grown up in poverty following his father's death and, before being hired by the vizier al-Afdal (his predecessor), he had been working low-status jobs which reportedly included learning building skills.

[7] The plan of the mosque of al-Aqmar is hypostyle, with an internal square courtyard surrounded by roofed sections defined by rows of four-centered arches.

The novelty of the floor plan lies in the facade's alignment with the street in contrast with its interior space, which remains oriented towards the qibla.

[2] This design is similar to the Mosque of al-Salih Tala'i, built by the Fatimids later in the same century, whose shops have been excavated and are visible today below the street level.

The Qur’anic inscription around the medallion starts on the lower right side, stating: “In the name of Allah, the Beneficent, the Merciful, O People of the House [ahl al-bayt] God only desires to put away from you abomination and with cleansing to cleanse you.”[10] The Fatimids interpreted this Qur’anic inscription as a reference to themselves, using it as a statement of legitimacy and manifestation of Shi'i ideology.

It is important to note that the right side of the portal was later covered by another building and its current state is a modern restoration and reconstruction by the Bohras, hence the stone's lighter color and smoother texture in comparison with the original masonry of the rest of the façade.

To the very left of the façade, there is a window grille framed by an arch resting on two small columns with the Muslim profession of faith above and roundels filling the spandrels in the names of Muhammad and 'Ali.

[15] Although the grilled window and the carved door panels represent real objects, their particular use as part of the façade's decorative scheme grants them a metaphorical meaning associated with the historical framework of Fatimid caliphal rituals.

Between the carved image of the window and of the doors there was once a decorative roundel or medallion which was later cut out and removed at some later unknown date, leaving the brickwork of the wall exposed.

[5] Scholar Doris Behrens-Abouseif has suggested that the original roundel was removed because it conveyed a message or concept that was later deemed unorthodox,[5] or because it because it contained an inscription glorifying al-Ma'mun which the caliph resented after the vizier's arrest.

It translates as follows:(Basmala, has ordered its construction ... the servant of our lord and master the imam al-Amir bi-ahkam Allah the son of the imam al-Musta'li) Bi'llah, commander of the faithful, may God's prayers be upon them and upon their pure and honourable ascendants, and their pious descendants, seeking the favour of God, the King, the Generous...O God, give victory to the armies of the imam al-Amir bi-ahkam Allah, commander of the faithful, over all the infid(els.....the most noble lord, al-Ma'mun amir of the armies, sword of Islam, defender of the imam), protector of the judges of the Muslims and the director of the missionaries of the believers, Abu 'Abd Allah Muhammad (servant of) al-Amir, may God strengthen religion for him, may He make the commander of the faithful enjoy long life, may He perpetuate his power and elevate his word, in the year 519 [1125-6].

The original decorative crenellations had disappeared by the early 20th century, but were recorded in drawings made by English architect James Wild in the 1840s.

[7] Only the lower part of al-Salimi's minaret survives, which is built of brick covered in stucco, topped with stone muqarnas, convex molding below, and a band of carved arabesques interrupted by openwork bosses in the middle.