[3] The crescent-chested puffbird was for a time called Malacoptila torquata but since the mid-1900s it has borne its current binomial.

However, BirdLife International's Handbook of the Birds of the World (HBW) treat those entities as separate species, the greater and lesser crescent-chested puffbirds respectively.

[6] The crescent-chested puffbird's nominate subspecies is found in southeastern Brazil from Bahia and Minas Gerais south to Paraná and Santa Catarina.

M. s. minor is found in a small disjunct range in Maranhão and Piauí states in Brazili's Northeast Region.

[6] The crescent-chested puffbird appears to be a mostly solitary forager though there are reports of it following army ant swarms with other birds.

[6] The IUCN follows HBW taxonomy and so has treated the two subspecies of crescent-chested puffbird as separate species.