Released in 1983, Kill 'Em All was the first album to completely feature everything that made the nascent Bay Area thrash metal scene so unique. The record's release saw many imitators and followers release albums in its wake, and set the band that made it on the path to "world domination", as drummer Lars Ulrich would put it in the following year.

The album reaches furious speeds on every track (discounting the Cliff Burton bass solo "(Anesthesia) Pulling Teeth"), a testament to the band's early influences: Diamond Head, Motörhead and Venom, all English bands who combined the heaviness and technicality of Black Sabbath with the speed and aggression of punk rock. This made the band a total anomaly in the early 1980s heavy metal scene in the USA. The band wear their influences on their sleeve, and shades of tracks like Diamond Head's "Dead Reckoning" can be heard in "Seek & Destroy".