This species is endemic to the Western and Eastern Cape Provinces of South Africa.

[1] Leptotyphlops nigricans is black or dark brown, both dorsally and ventrally.

Adults may attain a snout-vent length (SVL) of 196 millimetres (7.7 in).

Rostral as broad or slightly broader than the nasal, extending as far as the anterior border edge of the eye.

Ocular bordering the lip between two upper labials, the anterior of which is very small.