The crescent-chested warbler is superficially similar to both the northern parula and the tropical parula, with yellow underparts, a gray head, and a greenish back, but neither of these has a bold white eyebrow.

Adult males have a discrete chestnut crescent on the breast, which is less prominent and sometimes lacking in females and young birds.

These monogamous, solitary birds become more gregarious in winter, joining mixed-species flocks to feed (mostly insects, but sometimes fruits and berries in the middle to upper levels of trees).

It jumps from twigs and foliage, picking food from the underside of leaves, and hanging beneath leaves in a fashion similar to chickadees to check surfaces for prey.

Crescent-chested warblers make their nests atop grassy tussocks or sheltered by a hill or bank near the ground.