Sound of the Underground debuted to generally favourable reviews from contemporary music critics, who noted the high quality of the album compared to output from other reality show contestants.

[2] Their debut single "Sound of the Underground" was one of sixty songs that Brian Higgins and Miranda Cooper had written with the aim of launching their own girl group.

Girls Aloud worked with a variety of mostly British musicians and producers, such as Betty Boo, the Beatmasters, Graham Stack, Steve Anderson and Tim Kellett, and reunited with Higgins and Xenomania.

Girls Aloud deliberately waited five months after the release of "Sound of the Underground" in order to ensure they would have a strong second single.

When Higgins heard the remaining ten tracks that Girls Aloud had recorded for the album, he promptly called Polydor to complain about the lack of creative content.

"[11] This last-minute decision resulted in Girls Aloud returning to the studio to record a further four tracks with Xenomania – "Some Kind of Miracle", "Life Got Cold", "Stop" and "Love/Hate".

These four tracks, alongside an altered mix of "Life Got Cold", would eventually surface on a reissued version of Sound of the Underground, which was released on 17 November 2003.

Sound of the Underground takes influence from a number of 1980s genres, such as synthpop, power pop, and new wave, and 1990s styles like big beat, drum and bass, and garage.

"[17] Higgins said that "No Good Advice" reflected his general mood of failure after a special deal between Xenomania and London Records fell through in 2000, and about persisting in spite of what people told him to do or not to do.

[17][20] It was labelled "an enticing blend of spiky guitars and Fatboy Slim beats topped off with an irresistibly catchy chorus.

"[20] "Sound of the Underground" was further described as "a mechanistic sashay of twangy surf guitar and sultry gang vocals – Girls Aloud explodes like a five-headed Kylie Minogue.

"[22] The song was compared to "a 21st century Bangles", as well as former Spice Girls member and Popstars: The Rivals judge Geri Halliwell.

[15][23] "All I Need (All I Don't)" was described as "a Kylie-type tune set to squelchy techno", as well as "a disco-funk workout with traces of Cameo and Bedtime Stories vintage Madonna".

"[15] "Stop", a Xenomania production sung entirely by Nadine Coyle apart from the chorus, "starts like the Skids' "Into the Valley" but gets sultry instead of surreal.

[28] "Don't Want You Back" was co-written by Anders Bagge, who also wrote Samantha Mumba's "Gotta Tell You", which bears similarities.

[29] "White Lies" was co-written and produced by Tim Kellett, a former member of The Durutti Column, Simply Red, and Olive.

Cheryl Cole noted in Girls Aloud's autobiography Dreams That Glitter – Our Story (2008) that the single "was the point when we realized everything we'd been doing was quite down and moody [...] and that's not what people wanted."

Sound of the Underground was released in Ireland on 23 May 2003 and in the United Kingdom and European countries three days later, through Polydor Records and Universal Music Group.

It replaced the original bonus tracks and "Don't Want You Back" with three new songs: "Jump", "You Freak Me Out", and "Girls on Film".

Sound of the Underground and other Girls Aloud releases were made available for sale on the US iTunes Store on 26 June 2007 through Interscope Records.

On 26 March 2023, it was reported that the remaining members of Girls Aloud are to share unreleased tracks from the archives, to celebrate the 20th anniversary of the album.

The music video was shot in a London warehouse just days after Girls Aloud's formation in the last week of competition of Popstars: The Rivals.

The video for "No Good Advice" features the members of Girls Aloud clad in metallic, silver, futuristic outfits which can also be seen on the cover of this album.

The Times noted that Sound of the Underground "is packed with everything you want from a pop record – attitude, aggression, guitars, disco beats and steals from Phil Spector.

"[22] BBC Music said "time will tell if they are set to take the mantle as the new Spice Girls or slip rapidly down pops dumper as the new Hear'Say.