There are 10 species of birds in this family. They are medium to large-sized wading birds. They are usually found in dry, tropical habitats in Africa, Europe, South America, Asia, and Australia.

One species that breeds in North America, the Double-striped Thick-knee (Burhinus bistriatus), is found from southern Mexico south to northern Brazil.

Thick-knees have long legs with large knee joints, strong yellow or black bills, and large, round yellow eyes. They are speckled sandy-brown with white undersides.

Thick-knees are mostly nocturnal (active at night). During the heat of the day, they stay hidden under bushes. At night, they can be identified by their distinctive wailing calls.

They eat insects and other invertebrates; some species will also eat small mammals and lizards.

Species include the Eurasian Thick-knee (Burhinus oedicnemus), the Great Thick-knee (Esacus recurvirostris), the Senegal Thick-knee (Burhinus senegalensis), and the Peruvian Thick-knee (Burhinus superciliaris).