Alta Tensão is one of the pioneering heavy metal bands from Campo Grande, Mato Grosso do Sul, founded in the early 1980s by Edson David and brothers Adilson and Marcos Fernandes. The band released three albums — "Metalmorfose" (1984), "Portal do Inferno" (1986), and "Nigeria" (1990) — with "Portal do Inferno" earning recognition from international heavy metal critics; after disbanding in 1993, they reunited in 2017 with a new lineup.

Ambition is a heavy metal and hard rock band from Curitiba, Paraná, Brazil, playing a straightforward blend of classic heavy metal riffs and hard rock energy. The band released material through Infernö Records, a French underground metal label known for promoting underground acts. They represent Curitiba's growing metal scene, a city that has produced a number of important Brazilian black and extreme metal bands.

Amenaza is a heavy metal band from José C. Paz, Buenos Aires, Argentina, who released their self-titled debut in June 2020. The tape-released album spans 17 tracks and showcases the band's raw approach to traditional heavy metal within the greater Buenos Aires underground scene.

Amplifires is a heavy metal band from Jacareí, São Paulo state, Brazil, founded in 2004 and still active. Part of the interior São Paulo heavy metal underground, they have maintained an independent presence in the Brazilian scene for over two decades.

Amurians is an all-female heavy metal band from São Paulo, Brazil, formed in 2018. Their name and identity are rooted in the legend of the Icamiabas — an indigenous matriarchal warrior tribe of the Amazon region — and two of the members carry indigenous ancestry through their maternal grandmothers; the band channels this heritage into forceful, traditional heavy metal with a message of female empowerment in the Brazilian underground.

Anarca was a heavy metal band from São Paulo, Brazil, formed and disbanded in 2024. Despite their brief existence, they emerged from São Paulo's prolific and competitive heavy metal underground before splitting up in the same year they were founded.

Angant is a heavy metal quartet from São Bernardo do Campo, São Paulo, playing a classic-influenced style drawing on Judas Priest, Accept, and early Metallica. Their 2018 debut EP "Deep and Far" — released through Tratore — showcases tight riffing, melodic choruses, and well-balanced production across four tracks, marking a confident start for the band.

Anglachel was a traditional heavy metal band from Jaguariúna, São Paulo, drawing heavily from the New Wave of British Heavy Metal with Iron Maiden-influenced twin guitar harmonies and dual vocals. The band released a demo in 2003 and the four-track single "Hellish Domains" in 2005, earning comparisons to Bruce Dickinson-era Iron Maiden before eventually ceasing activity.

Anguish Project is a Brazilian heavy metal band led by bassist and composer Kaô (ex-Venus), with vocalist Sergio Faga (Children of the Beast) and guitarist Denis Okuma. Their 2025 debut album "What's Believing?" was mixed by producer Roy Z and features guest appearances from musicians tied to Viper, Angra, and Dr. Sin, combining classic heavy metal songwriting with philosophical lyrical themes drawn from Freud and Schopenhauer.