Ameaça Nuclear — Portuguese for "Nuclear Threat" — was a death metal and grindcore band from São Paulo, Brazil, active from 2020 until their split. The band operated in the tradition of São Paulo's brutal underground extreme metal scene, blending the raw aggression of grindcore with death metal's heavier structures. Their Bandcamp presence documents their brief but intense run in the city's tightly knit extreme metal circuit.

Amen Corner is one of the pioneering black metal bands in Brazil, formed in 1992 in Curitiba, Paraná, and widely regarded as a foundational force in the development of the country's extreme metal underground alongside acts like Murder Rape. Drawing influence from Venom, Celtic Frost, and Bolt Thrower, the band forged a sound characterized by diabolic weight and aggression, releasing landmark early albums including "Fall, Ascension, Domination" (1994) and "Jachol Ve Tehilá" (1995). Their 2024 album "Written by the Devil", released through Dutch label Hammerheart Records, marked their first international licensing deal after over three decades of activity.

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.

Amenthis was a death metal band from Ceilândia, in the Distrito Federal region of Brazil, with roots in the early 1990s underground scene. The band released a promotional demo titled "Dualism" in 1994 through Genocide Productions, placing them among the first wave of death metal acts to emerge from Brazil's capital satellite cities. Though they eventually split up, their demo stands as a document of the rough, early death metal sound that characterized the Brazilian underground at the time.

Ammit is a death metal and deathcore band from Belo Horizonte, Minas Gerais, Brazil, named after the Egyptian mythological demoness — part lion, hippopotamus, and crocodile — who devoured the hearts of the unworthy dead. The band incorporates lyrical themes drawn from hermetic philosophy and Egyptian mythology, and their sound blends the technicality of modern death metal with the heaviness of deathcore. They gained early visibility opening for Ukrainian metal act Jinjer on the band's Brazilian dates.

Amnistia is a thrash metal band from Itabuna, Bahia, Brazil, representing the northeastern corner of the country's thrash underground. The band plays aggressive, no-frills thrash with a regional identity that separates them from the São Paulo-centric thrash wave that produced acts like Sepultura and Ratos de Porão. Itabuna, a city in the interior of Bahia, has a small but dedicated metal scene, and Amnistia has been an active presence in it since their formation.

Amonicide was a thrash metal band from Brasília, Brazil, active from 2019 until their split-up. Hailing from the Brazilian capital — a city with a smaller but dedicated underground metal scene compared to São Paulo or Belo Horizonte — they operated as an independent act within the country's thrash tradition.

Amordazados is a thrash metal and crossover band from Barcelona, Anzoátegui, Venezuela, formed in 2005. The band released their debut EP Nacimos sin derecho a vivir in 2007 and their first full-length Nuestro odio in 2016.

Amort is a black metal band from Diadema, São Paulo, Brazil, formed in 2007 and still active. Based in the industrial ABC Paulista region just south of São Paulo, the band draws on Satanic and blasphemous lyrical themes common to Brazilian black metal, operating independently as part of the country's underground extreme metal scene.