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) [XC879304]
by Allen T. Chartier from Fazenda Rio Negro, Rio Negro, Aquidauana, Mato Grosso do Sul, Brazil (song)
Scarlet-headed Blackbird (Amblyramphus holosericeus) [XC481409]
by Pedro Rinaldi from Rocha Department, Uruguay (begging call, call)
Subspecies
No subspecies.
Analysis of mitochondrial DNA suggests relationship with Curaeus, but the two genera differ morphologically and behaviourally.