The slate-throated whitestart is a long-tailed warbler measuring 12 cm (4.7 in) long.
It has a deep rufous head, dark back, and contrasting bright yellow breast, belly and white vent and tail tips.
The bill is black, and the legs are blackish-gray.

While most of its plumage changes little throughout its large range, the underparts grade from yellow in most of its range, to red in the northernmost part.
The slate-throated whitestart is a long-tailed warbler measuring 12 cm (4.7 in) long. It has a deep rufous head, dark back, and contrasting bright yellow breast, belly and white vent and tail tips. The bill is black, and the legs are blackish-gray.
While most of its plumage changes little throughout its large range, the underparts grade from yellow in most of its range, to red in the northernmost part.
Slate-throated whitestart