Arsenal was a thrash metal band from Itajaí, Santa Catarina, active from 2011 until their split. Based in one of Santa Catarina's coastal cities, they contributed to the state's underground thrash scene before disbanding.

Arsênio is a thrash metal band from Foz do Iguaçu, Paraná, formed in 2012 in the tri-border city where Brazil meets Argentina and Paraguay. The band carries the aggressive, old-school thrash tradition of the Brazilian underground.

Art of Khaos was a progressive power metal band from Brasília, Distrito Federal, active until around 2020. Their 2018 album Monster Inside drew comparisons to Symphony X and Lamb of God, blending technical guitar work and heavy riffing with the melodic songwriting of progressive power metal.

Art of Torture is a brutal death/grind band from João Pessoa, Paraíba, playing gore-laden extreme metal in the vein of the Brazilian brutal death underground. Their 2015 album Impulse to Mutilation, recorded across studios in João Pessoa with David Nunes on vocals and André Toledo on guitars, delivers relentless blasting brutality across eleven tracks.

Arte Grotesca is a death metal band from Rio de Janeiro formed in early 2024, delivering a brutal and visceral sound with lyrics exploring grotesque and tragic human themes. Their debut album The Grotesque Gift of Human Games marks their entry into Rio's extreme metal scene with a dark and uncompromising approach.

Artes Negras is a black/thrash metal band from Buenos Aires, Argentina whose lyrical themes revolve around paganism, death, and Argentine werewolf folklore (the Lobizón). Their debut album "Let There Be Death" was released on CD in 2004 and featured members performing under pseudonyms including Necromandus on vocals, Lordnatt and Nan Noctambulus on guitars, Hellbastard on bass, and Funeris on drums.

Artilharia was a thrash/death metal band from Jaguariúna, São Paulo, with earlier roots in the band Hellhunter before a name change. Playing aggressive, garage-style extreme metal with Portuguese-language lyrics in a style reminiscent of 1980s Brazilian thrash, they released the demo Assassinos do Abismo before splitting up.

Artless was a thrash metal band from Petrópolis, Rio de Janeiro, active in the early 2000s before splitting up. Based in the mountain city roughly 70 km from Rio de Janeiro, the band operated within Brazil's underground thrash scene during a period when the genre was experiencing a renewed wave of activity in the country.

Arya Aryanna was a one-person extreme metal project from Buenos Aires that drew on slamming brutal deathgrind and breakcore, releasing albums including Anhedonia and Grotesque before going inactive. The project worked across an unusually wide sonic range, blending blackened death metal with electronic and industrial textures in a self-produced setting.