The double-striped thick-knee is a medium-large wader with a strong black and yellow bill, large yellow eyes, which give it a reptilian appearance, and cryptic plumage. The adult is about 18–20 in long and weighs about 27.5–27.7 oz. The head has a strong white supercilium bordered above by a black stripe. Juveniles are similar to adults, but have slightly darker brown upperparts and a whitish nape.
The double-striped thick-knee is striking in flight, with a white patch on the dark upperwing, and a white underwing with a black rear edge.