North-eastern Bolivia (Beni and Santa Cruz), most of Paraguay, and southern Brazil (southern from southern Mato Grosso and Santa Catarina, occasionally Paraná and possibly also Sío Paulo) south to north-western and eastern Argentina (northern Salta, Córdoba, and eastern Chaco south to Buenos Aires) and Uruguay.
 
Population
Estimated population is unknown (2010).
Scarlet-headed Blackbird (Amblyramphus holosericeus) [XC195212]
by Diego Caiafa from Ceibas, Gualeguaych\u00fa, Entre Rios, Argentina (song)
Scarlet-headed Blackbird (Amblyramphus holosericeus) [XC879296]
by Alvaro Riccetto from Fazenda Rio Negro, Rio Negro, Aquidauana, Mato Grosso do Sul, Brazil (song)
Subspecies
No subspecies.
Analysis of mitochondrial DNA suggests relationship with Curaeus, but the two genera differ morphologically and behaviourally.