A tiny, short-tailed songbird. Male is glossy-black above with a scarlet rump, and whitish below with a striking red throat bordered black and a black stripe running down the belly. Female is dull gray above with a red rump and whitish underparts. Juvenile resembles female, but pale-billed. Singles and pairs can be found in forest, forest edge, woodlands, and plantations in lowlands and foothills. Male differs from male Blood-breasted Flowerpecker in white underparts and black border below throat. Female Red-chested Flowerpecker is paler above than female Blood-breasted. Gives a very high-pitched song, “tzit-wut-zoo,” lower-pitched on the last note. Also gives short, sharp “tzit” calls.