Cienfuegosia hildebrandtii is an upright subshrub or a perennial herb up to 1.5 m tall. The branchlets are sparsely hairy to velvety. The leaves are simple, smooth, with a V-shaped base. The leaf blade is shaped like a fan, ranges from 60–70 mm wide, the margin is toothed in the upper half or can be 3–5 lobed but not deeply. They are densely covered in many short, straight hairs to nearly hairless. The petiole is up to 20 mm long. Stipules are up to 10 × 6 mm, heart-shaped to rounded, resembling the leaf, and surrounding the stem.

The flowers are 60–80 mm in diameter, yellow with a dark red to maroon centre. They are borne singly, in the axils of the leaves, towards the tips of the branches, or sometimes in 2- or 3-flowered sympodial inflorescences; this is where the bud forms in the secondary axis, and the next bud also forms in the secondary axis, and continues following that pattern, 2 or 3 times in this case. The peduncles can be up to 25 mm long, growing from the node, articulated near the base. The epicalyx has up to 10 bracts, below the calyx, each bract about 2–3.5 mm long, linear. The calyx is 10–13 mm long, 15-nerved, hairy to nearly hairless. The calyx lobes resemble an oval shape, with a short, sharp apex, and are joined at the base for 8–9 mm. The petals are yellow, about 4 × 6 mm, slightly twisted, resembling a turned-upside-down oval, with star-shaped hairs on the outside, but completely hairless inside. The staminal tube is 7–8 mm long, the filaments 4–6 mm long, the style protruding 10 mm beyond the staminal tube. The fruit is a capsule, 10–12 × 8–10 mm, covered with closely pressed down, fine hairs, that are straight, not star-shaped. It also has small black oil glands, that are more concentrated towards the tip of the fruit skin. The seeds are covered in brownish silky floss. Flowering is in summer and autumn (November to April).

The flowers look similar to those of Gossypium herbaceum and may cause these species to be confused for each other, however they are easy to tell apart when in fruit because Gossypium herbaceum has long, white hairs attached to the seeds where Cienfuegosia hildebrandtii has shorter, brown hairs.