Formed in San Francisco in 1981 by guitarists Gary Holt and Kirk Hammett (future founder of Metallica) to play the conventional hard rock spreading in the Bay Area, Exodus slowly progressed toward thrash metal. With the lineup settled around Rick Hunolt on second guitar and Paul Baloff on vocals, in 1985 they recorded the album Bonded By Blood (Torrid). Here, amid horrifying scenes and blatant self-parodies, starting with the deranged anthem "Exodus", unfolds a perverse ritual of frantic cadences, galactic solos, and gory lyrics. Exodus display a morbid fascination with the aesthetics of evil, which materializes in the werewolf revelry of "Strike To The Beast" and the satanic sabbath of "And Then There Were None"; but the true nature of this horde of outlaws hardened to every vice emerges in the delirious calls to arms of "Metal Commando" and "Piranha": inciting the headbangers to devastate and mutilate, commanding not to take prisoners, wishing agonizing deaths—Holt and company wrote ideal guerrilla manuals for the most ruthless urban gangs. Equally divided between satanic rituals and urban hooliganism, the tracks of this work have few rivals in terms of ideological ferocity and sonic extremism. It represents a further moral regression compared to the scornful cynicism of punk.

Steve Souza (from Legacy, later Testament) replaced Baloff for the follow-up Pleasures Of The Flesh (Combat, 1987). Less inspired than its predecessor, the unrestrained gallop was replaced by a stubbornly cadenced ( "Parasite" ) and armored ( "Brain Dead" ) pace. The hedonistic ritual of the title track and the grim messianism of "Seeds Of Hate" are not enough to give the work an identity, so much so that the band ends up imitating AC/DC ( "Till Death Do Us Part" ).

Better results came in 1989 with Fabulous Disaster, in which Exodus tried to move beyond the form by introducing exotic rhythms (making a ballad like "Low Rider" even more sinister) and pairing their martial-paced salvos with catchy refrains (the memorable "Toxic Waltz" ). Also thanks to Souza’s hoarse tone, one has the impression (both in the title track and in "Cajun Hell") that the aim was to transport the wild rock and roll of AC/DC into a thrash context (all the way to the muddled babbling of "Verbal Razors" ).

Still searching for life after thrash, the group attempted further commercialization with Impact Is Imminent (Capitol, 1990).

Exodus are exemplary of how thrash metal needed to break free from its narrow premises right away to avoid endless repetition; but they are also exemplary of how difficult it is to succeed in doing so.

Exodus returned with the vicious Tempo of The Damned (Nuclear Blast, 2004), notably especially for the extended solos.

Shovel Headed Kill Machine (2005) featured neither Zetro nor Baloff.

The Atrocity Exhibition - Exhibit A (2007) also featured lengthy solos.