Parallel Lines was the first in a series of Blondie albums to be produced by Mike Chapman who they met during a tour in 1977. In contrast to Richard Gottehrer, who produced the band's first two albums with a more casual approach, Mike Chapman was a perfectionist who drove Blondie to do perfect timing and basic tracks, to double or triple their parts, doing and redoing them multiple time as the occasion demanded. It was also the first album produced by Chapman that he did not contribute any songs to.
The name of the album comes from an unfinished Blondie song about communication, characterisation and eventual meeting of different influences. The lyrics for the song were listed in the liner notes for the album's first vinyl edition. Another unreleased song from the album sessions, "Underground Girl", was later issued on the compilation albumBlonde and Beyond.
According to Rolling Stone magazine's Arion Berger, Parallel Lines eschewed "cartoonish postmodernist referencing" of Blondie's previous new wave songs for a "romantic fatalism" that was new for the band. "Sunday Girl" deals with the theme of teen loneliness, while "Fade Away and Radiate" is about falling in love with dead movie stars. On the latter song, Debbie Harry, who daydreamed as a child that Marilyn Monroe was her birth mother, compares a flickering image onscreen to the light of a dying sun. Music critic Rob Sheffield said that the lyric "dusty frames that still arrive / die in 1955" is the "best lyric in any rock'n'roll song, ever, and it's still the ultimate statement of a band that always found some pleasure worth exploiting in the flashy and the temporary."
In a retrospective review for Blender magazine, Robert Christgau said that Parallel Lines was "a perfect album in 1978" and remains so with "every song memorable, distinct, well-shaped and over before you get antsy. Never again did singer Deborah Harry, mastermind Chris Stein and their able four-man cohort nail the band's signature paradoxes with such unfailing flair: lowbrow class, tender sarcasm, pop rock."Q magazine called the album "a crossover smash with sparkling guitar sounds, terrific hooks and middle-eights more memorable than some groups' choruses." Christian John Wikane of PopMatters called it "a creative and commercial masterpiece by Blondie" and "indisputably one of the great, classic albums of the rock and roll era."Sasha Frere-Jones, writing in Spin, said that it may have been "the perfect pop-rock record".Pitchfork Media's Scott Plagenhoef credited the album for popularizing "the look and sound of 1980s new wave".
Parallel Lines was ranked at number 140 on Rolling Stone magazine's list of The 500 Greatest Albums of All Time, number 18 and 45 on NME's 100 Best Albums of All Time and 500 Greatest Albums of All Time respectively, and number 7 on Blender's 100 Greatest American Albums of All Time.Rolling Stone wrote that the album was "where punk and New Wave broke through to a mass U.S. audience". The album was also ranked at number 94 by Channel 4's list of 100 greatest albums of all time.
Parallel Lines contains several of Blondie's best-known hits, including "Heart of Glass", "Hanging on the Telephone", "Sunday Girl" and "One Way or Another". Six of the twelve tracks were issued as singles, either in the US or the UK. It is notable that the original album version of "Heart of Glass", also a single version in the UK, was replaced with the longer disco version on pressings of the album released as of March 1979. However, the original surfaced on some later reissue editions.
On June 24, 2008, an expanded 30th Anniversary Edition of the album was released, which featured new artwork and bonus tracks along with bonus DVD. The liner notes once again featured lyrics to unfinished "Parallel Lines" song. The Parallel Lines 30th Anniversary Edition included the 7" single version of "Heart of Glass", which was featured on the original pressing of the album, the French version of "Sunday Girl" and some remixes, plus a DVD with albums promo videos and TV performance.
The album version of "Heart of Glass" was replaced with the disco version (5:50 minutes long) on pressings of the album released as of March 1979. The original length version of "Heart Of Glass" appeared on the original US CD release in 1985 Chrysalis VK 41192 [later F2 21192] although the CD artwork proclaimed it was in fact 'Disco Version'. Later editions of the Capitol disc had the mistake removed from the inlay but it remained on the disc until its deletion. 1994 DCC Compact Classics Gold CD release [Capitol Special Markets USA] GSZ 1062 features original version (3.45) with 5'50 version as a bonus track – this edition also featured booklet with full song lyrics. Chrysalis through EMI/Toshiba in Japan issued Parallel Lines with a mini LP card sleeve in 2006 - notable for its reproduction inner sleeve complete with lyrics and Chrysalis Records label on the actual disc.
A promotional CD of the album was given away free with the British newspaper The Mail on Sunday on 5 December 2010, including the bonus tracks "What I Heard" and "Girlie Girlie" from the band's 2011 album Panic of Girls.