Astroloba cremnophila is a slow-growing, long-lived, succulent perennial, forming small, dense clusters, branching from the base, up to about 400 mm in diameter and consisting of about 12–60 heads, mainly pendent from cliff faces. The branches are 50–200 mm long; the leafy stems about 35–38 mm in diameter, glaucous green, becoming reddish green during the dry periods. Leaves are ascending, erect, in 5, spirally twisted rows, densely arranged, like tiles on a roof; triangular to egg-shaped, firm, 22–25 × 12–15 mm, with a distinct marginiform keel, apex acute to acuminate, minutely denticulate-tuberculate; margin leathery, with small saw-edged teeth (serrulate). Adaxial surface somewhat channeled, faintly striate; abaxial surface tuberculate; tubercles greenish white.

Inflorescence a simple raceme, 120–460 mm long; scape 2.0–2.5 mm wide at the base, with raceme in upper half to one third. Bracts membranous; lower bracts up to 5 mm long, triangular-acuminate, whitish translucent; floral bracts 2.5–3.0 mm long, translucent with darker median stripe. Flowers 3–10 mm apart, sub-secundly arranged, ascending spreading. Pedicel 3 mm long. Flowers tubular, 11 × 2.5 mm; lobes fused into a tube, slightly curved, free for 1.5 mm, grey-green, with white stripes; outer lobes spreading, apices truncate to emarginate; inner lobes obtuse, curved inwards. Stamens 8–9 mm long, anthers 5 mm long. Ovary oblong, 3.5 × 1.5–2.0 mm, green, styles 3 mm long, stigma minute, white, capitate. Capsule linear ovoid 7 × 3 mm. Seeds not seen. Flowering time is in summer, from November to April.