"The Hardest Part" is a song released as a second single from Blondie's fourth album Eat to the Beat in the United States and Canada, instead of "Union City Blue" which was issued in Europe. It was written by the group's principal songwriting partnership, Deborah Harry and Chris Stein. The single had minor success, reaching #84 and #86 on the Billboard Hot 100 and RPM 100 Singles respectively. It is generally considered that the relatively poor chart placement can be blamed on the overwhelming radio response to "Call Me"; with the glossier pop track being released just a month after the punk-pop "The Hardest Part". Clearly, the commercial appeal of "Call Me" and the success of the American Gigolo film strongly overshadowed this releases chance for chart success.
As with all songs on the album, a music video was produced to promote the single. It features Debbie Harry wearing a dress designed by Anya Phillips, who also designed the pink dress featured on the cover of the band's 1978 album "Plastic Letters". The video was directed by David Mallett.