South-eastern Brazil from central Bahia (Chapada Diamantina) south to northern Rio Grande do Sul, also adjacent eastern Paraguay (Alto Paraná, Itapúa) and north-eastern Argentina (Misiones, north-eastern Corrientes).
 
Population
Estimated population is unknown (2010).
Black-billed Scythebill (Campylorhamphus falcularius) [XC340032]
by Mateus G. Santos from Macarani, Bahia, Brazil (song)
Black-billed Scythebill (Campylorhamphus falcularius) [XC670295]
by JAYRSON ARAUJO DE OLIVEIRA from Garuhap\u00e9, Libertador General San Mart\u00edn, Misiones, Argentina (call, subsong)
Subspecies
No subspecies.
Sometimes thought to form a superspecies with Red-billed Scythebill (Campylorhamphus trochilirostris). Regarded by some authors as conspecific, an arrangement disputed by most. Close relationship with Curve-billed Scythebill (Campylorhamphus procurvoides) is also suggested.