Sansevieria hyacinthoides is a robust, evergreen, perennial herb, up to 600 mm high. Its rhizomes are sturdy, fibrous and bright orange. The leaves are erect, borne in pairs of 5–12 in loose clusters, arising from the ground, broadly lanceolate to ovate, flat, ± 600 × 80 mm, dark green with paler markings, and margins red.

The inflorescence is a many-flowered raceme, ± 450 mm high. The flowers are stalkless, white, cream-coloured or greenish white to pale mauve; borne in clusters, fairly scented, opening at night. Sansevieria hyacinthoides flowers in September to May. The fruit is an orange berry, ± 8 mm in diameter.

Mother-in-law’s tongue can be confused with Sansevieria metallica (giant sansevieria), which is a robust plant and grows up to 1.6 m tall. The giant sansevieria has 2 or 3 leaves, ± 1 m high, pale green with white markings and deeply channelled. Its flowers are caramel-toffee-scented. It is naturally found in sand forest of northern Kwa Zulu–Natal extending to tropical Africa.