Wingspan 14-18 mm.
The adults of this species, unlike some of the other Lampronia species, are relatively plain in appearance.
The moth is quite local in Britain, occurring scarcely in a few widely scattered localities throughout. It flies in May and June, during the afternoon.
The larva is unusual in that it forms a swelling, or gall on a twig of birch (Betula), usually at a node, within which it feeds.
The presence of reddish-brown frass around the exit hole indicates a larva within.