Abütre is a black metal band from Porto Alegre, Rio Grande do Sul, Brazil, formed in 2024 and part of the state's active underground extreme metal scene. A recently formed act with minimal documented output, they operate within the raw, underground tradition of Brazilian black metal.

Acacia Caven is a black metal duo from Córdoba, Argentina, formed in 2021. The band released their self-titled debut EP in July 2021, a five-track digital release spanning raw black metal and post-black metal textures with tracks including "Asfixia," "Vacío," and "Vidrio." Their music also appears on the label GSP Bandcamp, widening their reach within the Argentine underground scene.

Accipiter is a heavy metal band from São Paulo, Brazil, formed in 2014 and active in the city's underground traditional metal scene. With a minimal public profile, the band operates independently, carrying forward the São Paulo heavy metal tradition that has produced some of Brazil's most storied acts.

Aceldama is a stoner/doom duo from Quilmes, Buenos Aires, Argentina, built around guitarist and vocalist Ayatola el Infame and drummer El Musulmán. Their 2023 release "Demasiado tarde..." — recorded at El Portón studio — stretches across four sprawling tracks including the ten-minute closer "Estramonio," sitting comfortably in the heavy psychedelic and doom tradition. The album's full subtitle, referencing being "too late to think about God," signals the band's bleak, riff-driven worldview.

Acid Angel was a thrash metal band from São Bernardo do Campo, in the greater São Paulo metropolitan area of Brazil, formed in 1989 and active through the mid-1990s before splitting up. Operating as an independent underground act, the band was part of the wave of Brazilian thrash that flourished in São Paulo's industrial satellite cities during the late 1980s and early 1990s.

Acid Blood is a thrash metal band from Brasília, Distrito Federal, Brazil, active in the capital's relatively compact but dedicated underground metal scene. The band operates independently, delivering straight-ahead thrash metal that draws on the classic Brazilian and international thrash traditions cultivated since the 1980s.

Acid Brigade was a thrash metal band from Londrina, Paraná, Brazil, active from 2016 to around 2019. They released the demo "Addiction to Distortion" in 2016 and followed it with their full-length "Storming Into This Land" in 2019, a record tracked at Toque Grave Estúdio and noted for its palm-muted riffing and old-school new-wave-of-thrash energy.

Acid Evil is a one-woman Thrash Metal act from Quito, Ecuador, active since 2009 with the same member handling all instruments and vocals throughout the band's existence. The project released its debut demo Black Space in 2010 and full-length Multidimensional Past in 2019, signing with Triple Goddess Recs for the 2024 EP Saturnian Kult.

Acid Funeral is a Brazilian black/doom metal duo formed in 2024, consisting of vocalist Niili and multi-instrumentalist Billy Grind. Released through the DIY label Podreira Records out of Catanduva, São Paulo, their debut EP "The Doom Cult" (2024) fuses corrosive black metal atmosphere with slow doom riffing under the self-described banner of "Doom Rituals on Acid."