Ajayu is a black metal band from El Alto, Bolivia, signed to Infernal Possession Productions. Their self-titled full-length, released in 2017, is described as a work drawn from the soul exploring the complex nature of human emotion, placing them within a small but active circle of extreme metal acts operating out of Bolivia's high-altitude urban centers.

Ajeno is an instrumental sludge and groove metal band from Buenos Aires, Argentina, known for heavy, riff-driven compositions without vocals. The band released their self-titled EP followed by Justificando el Kaos in November 2024, a three-track record recorded at Estudios Inclan and La Ochava Records. Both releases showcase a dense, slow-burning approach rooted in the heavier end of sludge and post-metal.

Ajna is an industrial thrash metal band from São Paulo fronted by vocalist Elizabeth Queiroz (known as Tibet), blending guttural female vocals with samplers, industrial collages, and aggressive thrash riffs. Originally formed in 1990 and reunited in 2015, they released the EP "War Crimes" in 2019 — produced by Marcelo Pompeu of Korzus — and have performed at venues including Centro Cultural São Paulo and festivals such as Metal Attack.

Aka Funeral is a black metal band from Belo Horizonte founded in 2014, centering their work on Luciferian Gnosis, occultism, and philosophy. Their debut album "Stormy Tide" (2016) was recorded at Riff Studio with a logo designed by Christophe Szpajdel, and they followed it with the full-length "The Endless Eye" (2019) released through Songs for Satan on a limited pressing of 500 copies.

Akaamelda is a one-man melodic death metal project from Buenos Aires, created by Alexey Ermakov, that draws on the classic Scandinavian style of the genre. The debut album Death Equals Relief was released in November 2024, followed by the expanded Epitaph Edition in March 2025, featuring thirteen tracks built around melodic guitar harmonies, heavy riffs, and themes of grief and despair. The project blends melancholic atmosphere with the high-energy drive of early 1990s melodic death metal.

Akallabêth was a folk metal band from Aracaju, Sergipe, whose very name comes from J.R.R. Tolkien's account of the downfall of Númenor — a fitting tribute for a band weaving fantasy-literary themes into their heavy sound. Active in the 2010s before splitting up, they were one of the few extreme metal acts to emerge from Sergipe's underground scene.

Akerbeltz is a black metal band from Contagem/Belo Horizonte, Minas Gerais, formed in the mid-1990s and drawing explicitly on the old-school traditions of Bathory and Hellhammer. They released "Therion Rising" in 1999 on Cogumelo Records — one of Brazil's most storied metal labels — and returned with "Akerbeltz Coven Rising" in 2011, maintaining their Satanic and pagan black metal aesthetic across both records.

Akeronte is a thrash metal band from Haedo, in the Buenos Aires metropolitan area, built around the aggressive, riff-forward sound of classic Bay Area and South American thrash. The band released two EPs early in their career — Mientras los Reyes Ríen in 2009 and Epidemia in 2010 — establishing their place in Argentina's underground thrash scene. The current lineup features Diego Atienza on vocals and guitar, Julian Cortina on guitar, Leandro Lebenas on bass, and Lucas Flores on drums.

Akinetopsia is a brutal death metal trio from São Paulo formed in 2022, consisting of Evandro Miranda (vocals/guitar), Juan Azevedo (bass/vocals), and Daniel Oliveira (drums). Signed to New Standard Elite, their debut full-length "Collapse of Continuum" (2022) drew attention in the international brutal death metal underground for its dense riffing and technical precision, with themes centered on mental illness and alienation.