The Black-thighed Grosbeak occurs only in the highlands of Costa Rica and western Panama, where it is an uncommon resident of the borders of humid montane forest, old second growth, and pastures with scattered trees. The Black-thighed Grosbeak has a typically thick Pheucticus bill. The plumage is mostly yellow, with a narrow black mask, black back and wings, a black tail, and black tibial feathers; there also is a white patch at the base of the primaries. This species is similar to both the Yellow Grosbeak (Pheucticus chrysopeplus) of western Mexico and Guatemala, and to the Golden-bellied Grosbeak (Pheucticus chrysogaster) of the Andes of South America (and some earlier authors classified all three as a single species). The Black-thighed Grosbeak usually is solitary or in pairs, which usually forage high in trees for insects and for many different fruit and seeds.