The Moustached Wren is distributed in Amazonia south of the Amazon and into eastern Brazil. It is found at the edges of forest and woodland in dense undergrowth often where there is bamboo present.

The name comes from the black line under the white malar streak. There is also a long white supercilium and black with white streaks around the ear. Otherwise the crown and nape are browny-grey while the remaining upperparts are rufous brown, the throat is white becoming grey and buffy lower down and the tail has black barring.