A medium-sized owlet-nightjar of foothill forests. Dark brown wings and tail with barring and some additional white flecks on the wings. Dark head, whitish belly and buffy base to the chest covered with irregular, dark arrowhead marks. Potentially co-occurs with Mountain, Vogelkop and Barred Owlet-Nightjars, but Wallace’s lacks the distinct barring of Barred and Vogelkop, and the pale collar of all 3 species. Voice a simple, whistled “pweet pyuut” with the first note falling and second lower. Sometimes just one of these notes given.