Wingspan c. 10mm.
Distributed in southern England and Wales, and also occurring in parts of northern England and Ireland, this species occurs in woodland habitats.
Similar Elachista species with a single yellowish fascia have a noticeable patch of pale cilia at the apex of the forewing, whereas those of E. gangabella are all dark.
The larvae feed on grasses, especially cock's-foot (Dactylis), soft-grass (Holcus) and false brome (Brachypodium), creating a transparent mine containing silk and frass.
There is a single generation, adults flying during May and June.