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) [XC50564]
by Carlos Ferrari from Lascano, Rocha, Uruguay (song)
Scarlet-headed Blackbird (Amblyramphus holosericeus) [XC510627]
by Jacob Wijpkema from Corredor do Pinheiro road, Cord\u00f5es Litor\u00e2neos region, Rio Grande, Rio Grande do Sul, Brazil (song)
Subspecies
No subspecies.
Analysis of mitochondrial DNA suggests relationship with Curaeus, but the two genera differ morphologically and behaviourally.