The inflorescence of Aloe cooperi is an unbranched, conical raceme growing on a flattened, erect peduncle that becomes terete (cylindrical) near its top. Up to three racemes may be grown from one plant per season. There are sterile bracts, ovate and pointed on the upper part of the peduncle. Many vein lines are visible on the bracts.
There are about 40 flowers in the raceme of about 20 cm long and up to 14 cm in diameter. The upper buds are exceeded in length by their narrow, pointed bracts. The pedicels of the lowest flowers may be up to 4,5 cm long. The flowers are orange or yellow-orange, sometimes salmon-pink. The fleshy, cylindrical to triangular perianths become up to 4 cm long and about 12 mm in diameter at the base. They narrow to the segment tips that are green.
The anthers are only exserted in flowers of some plants, while the stigma is exserted up to 5 mm.
Flowering happens from spring to early autumn, depending on the region (Reynolds, 1974; Craib, 2005; Van Wyk and Smith, 2003).