Southern Brazil (southern Mato Grosso east to western Minas Gerais and eastern Sío Paulo) and north-eastern Paraguay; possibly also south-eastern Bolivia.
 
Rarity Status
Currently this species is not classified as a rarity in this country OR information has not been updated.
Population
Estimated population is unknown (2010).
Closely related to the superspecies formed by Three-banded Warbler (Basileuterus trifasciatus) and Stripe-crowned Warbler (Basileuterus culicivorus). Occasionally hybridizing with Stripe-crowned Warbler (Basileuterus culicivorus) in area of range overlap in southern Brazil and north-eastern Paraguay.
Considered by some authors to be a subspecies of Stripe-crowned Warbler (Basileuterus culicivorus).