The rufous-winged ground cuckoo is long, about half of which is its tail. Males weigh about and females about . Adults have a heavy decurved bill that is black with a greenish to greenish white tip on the maxilla. The sexes are alike. They have a deep purplish blue head, crest, neck, and upper back and olive lower back and uppertail coverts. Their inner tail feathers are metallic purple and the outer ones black with a green gloss. Their wings' primaries are bluish black and the secondaries dark brownish red. They have bare red to reddish-violet skin around and behind the eye. Their throat is ashy to dark gray with black borders on the lower feathers that give a scaly appearance. Their upper breast is black, the lower breast and belly dull ashy brown to slate gray, and the undertail coverts slate gray. Juveniles have mostly brownish slate upperparts with a black lower back and rump and slate underparts.
