The red-and-black-grosbeak is 20.5 cm (8.1 in) long; one male weighed 48 g (1.7 oz). Both sexes have a heavy black bill and their entire head including the throat is black. The male's nape, breast, and belly are bright red and its back is a deep red. The female's upper parts are dark greenish yellow and the underparts yellowish green. The immature male has a similar color scheme to the adult but it is duller.
The red-and-black grosbeak is primarily found from far eastern Venezuela east through the Guianas and into northern Brazil. It has also been observered in Brazil south of the Amazon River. It inhabits mature humid terra firme and várzea forest from sea level to 1,000 m (3,300 ft).
The red-and-black grosbeak forages in the lower levels of the forest for arthropods and seeds. It does not join mixed-species foraging flocks but feeds in pairs or family groups.
No information has been published on the red-and-black grosbeak's breeding phenology.
