Gasteria tukhelensis is a more or less stemless succulent, up to 250 mm high. It proliferates from the base and forms clusters up to 700 mm in diameter with 3-8 heads. The roots are succulent and up to 5 mm in diameter. The leaves are brittle and are produced in rosettes. They are 120-250 mm long and 30-50 mm broad at the base, triangular-lanceolate, sickle shaped (falcate) and curve upwards and sometimes backwards. Both surfaces are smooth and shiny, and dark green with faint white spots arranged in obscure transverse bands. The upper surface becomes channelled during the dry season and the lower surface keeled. The leaf margins are minutely toothed to almost smooth, and the tips are rounded or end in a sharp point. The juvenile leaves are arranged in opposite rows (distichous) and they are erectly spreading to patent. They are strap-shaped and their surface is covered with small tubercles.

The inflorescence is a spreading raceme up to 560 mm long, often with two side branches. Up to 11 flowers may be open at the same time. The flower stalks are drooping and 12-17 mm long. The perianth is tubular, 40-43 mm long and about 6 mm wide and pink; the upper half is white with green striations. The stamens protrude shortly from the perianth. Flowering time: Midsummer (December to March in the southern hemisphere).

After fertilization the capsule, which is 23-32 mm long, becomes erect. When it dehisces the black, 5-7 mm long and 2-3 mm broad seeds are released.