Aloe pretoriensis grows a 1 m long stem upon which the 40 to 60 leaves of the single rosette are nearly erect when young. The leaves are lanceolate-acuminate, i.e. lance-shaped and tapering to a sharp tip.
The upper leaf surface is nearly flat while the lower one is rounded, the space between them filled with the succulence characterising Aloe leaves. Only the margins are armed with sharp, reddish, hard teeth. The leaf sap is pale yellow. Leaf colour is grey-green or bluish green, glaucous.
These plants are found in nature from Pretoria eastwards to Mpumalanga and Limpopo on rocky slopes in grassland and full sun. In bloom during May and June they are a feature in the veld near Roossenekal and Lydenburg.
The specific epithet still links the plant to Pretoria, the western end of the species distribution, serving as a reminder, once the city has fully morphed into Tshwane (Reynolds, 1974; Jeppe, 1969).