The great head, arms and legs of the Colossus were carved from white marble, while the rest of the body consisted of a brick core and wooden framework, possibly covered with gilded bronze.

The statue's right hand is said by Eusebius[1] to have held "a trophy of the Saviour's passion with the saving sign of the Cross", possibly therefore in the form of a staff with the sacred monogram XP affixed to it.

Eusebius further records the Latin inscription engraved below the statue, which may be translated as follows: Through this sign of salvation, which is the true symbol of goodness, I rescued your city and freed it from the tyrant's yoke, and through my act of liberation I restored the Senate and People of Rome to their ancient renown and splendour.

The head was perhaps meant to convey the transcendence of the other-worldly nature of the Emperor over the human sphere, notable in its larger-than-life-size eyes which gaze toward eternity from a rigidly impersonal, frontal face.

The sculptor has conceived this countenance as a holy mask, an overpowering cult object resembling, though on a far greater scale, the icons of future Byzantium: an idol animated with the divine presence, and with the power to repel the demons lurking in pagan images.

In 2024, a 1:1 scale reconstruction of the Colossus of Constantine was unveiled in Rome, as result of a collaborative effort between the Capitoline Superintendency, Fondazione Prada, and Factum Foundation for Digital Technology in Preservation.