An instant critical and commercial success, the album reached No. 1 on the UK Albums Chart in February 1979 and proved to be the band's commercial breakthrough in the United States, where it reached No. 6 on the Billboard 200 in April 1979. During a tour of the west coast of the US in support of Plastic Letters, Blondie encountered Australian producer Mike Chapman in California. Peter Leeds, Blondie's manager, conspired with Chrysalis Records to encourage Chapman to work with Blondie on new music.

Parallel Lines took its name from an unused track written by Harry, the lyrics of which were included in the first vinyl edition of the album. The cover sleeve image was photographed by Edo Bertoglio and was chosen by Blondie's manager, Peter Leeds, despite being rejected by the band. The photo shows the band in front of a background made up of alternating black and white vertical bars, with the male members of the band posing in matching dress suits and smiling broadly in contrast to Harry who poses defiantly with her hands on her hips while wearing a white dress and high heels.

TRACKLIST

Hanging On The Telephone
One Way Or Another
Picture This
Fade Away And Radiate
Pretty Baby
I Know But I Don't Know

11:59
Will Anything Happen
Sunday Girl
Heart Of Glass
I'm Gonna Love You Too
Just Go Away