The album spans several genres, but is generally noted for its extensive percussion and overall heavy sound. It was well received by fans and critics alike and was responsible for bringing Slipknot a large increase in popularity. The album peaked at number 51 on the Billboard 200, and has gone on to become certified double platinum in the United States, making it the band's best-selling album. It was voted the best debut album of the last 25 years by readers of Metal Hammer magazine.^[2]

The band's use of percussion, turntables and samples gives the album a dense, layered sound. Alternative Press hailed the "inventive sampling, creative guitar work and an absolute percussive overload",^[20] while Q described the album as "a terrifying racket".^[21] Slipknot also includes melody, notably in the single "Wait and Bleed".^[17]

"742617000027", the intro, contains guitar scratches and abstract sound samples by sampler Craig Jones. Some of the dialogue was reportedly taken from a Charles Mansondocumentary. The dialogue is, "The whole thing, I think it's sick." In an interview shortly after the album was released, Jordison claimed the voice is Corey Taylor's, sped up.^[22] "(sic)", recalled Jordison, was written "at the very first rehearsal I had with Slipknot, on September 15, 1995. We were called The Pale Ones then and the song was originally called "Slipknot". It sounded completely different as Corey wasn't in the picture at that point." (Corey Taylor appeared on Slipknot's second demo, which resulted in them signing to Roadrunner Records.^[23]) "Paul [Gray, bassist] and I wrote the song together many years before we started Slipknot," said Shawn Crahan. "We basically had the riff and the drum beat. But it wasn't '(sic)' until everyone else was in the band and we brought it to [producer] Ross [Robinson]." "All of us were in the same room when we recorded this. It was hilarious. Everyone had their headphones tied to their head so we could all slam and go crazy while we played. Ross was throwing potted plants at Joey. It was the most insane thing I'd ever seen."^[24] Rick Anderson of AllMusic noted that on "Scissors", Taylor "sounds like he's about to burst into tears."^[18] Taylor's aggressive, expletive-filled lyrics were noted by AllMusic: "[the] lyrics that are discernible are not generally quotable on a family website; suffice it to say that the members of Slipknot are not impressed with their fathers, their hometown or most anything else."^[18]

"Eeyore" – a hidden track at the end of "Scissors" – begins after dialogue shared among the band members, recorded while they were viewing a scene in a pornographic film that involved coprophilia.^[25] It has been played live many times and appears on the DVD Disasterpieces and the live album 9.0: Live.^[26]