The long, slender bill of the Black-winged Stilt is used like a pair of fine tweezers as the bird forages by pecking at tiny invertebrates on the water’s surface. Although this is its most common feeding method, stilts have been recorded using at least nine different methods to feed. They usually forage by wading in water up to belly deep, but also feed along the muddy margins of wetlands, regularly forming large, noisy feeding flocks, often in association with Banded Stilts and Red-necked Avocets.

The Black-winged Stilt is a large black and white wader with long orange-red legs and a straight black bill. It has black on the back of the neck, a white collar and a red iris. Both sexes are similar, and the plumage does not change during the year. Black-winged Stilts give a repeated high-pitched barking call. Young Black-winged Stilts lack black on the back of the neck and have grey-brown wings and back, speckled with white. They have a smudged grey crown, which extends down the back of the neck as the birds get older.

Black-winged Stilts are related to Banded Stilts, Cladorhynchus leucocephalus, which have a broad chestnut band across the breast (absent in young birds) and lack the black on the back of the neck. Young Banded Stilts can be separated from young Black-winged Stilts by their all white back and black wings.