"Smile" is Lily Allen's first mainstream single release, and was penned by Lily Allen, Iyola Babalola and Darren Lewis (the duo who produced the track as Future Cut). The Organ riff is a sample of Jackie Mittoo playing keyboards on Free Soul by The Soul Brothers, written by Jackie Mittoo.
The music video, directed by Sophie Muller (who also directed the video of previous UK number-one "Hips Don't Lie" by Shakira), shows Lily getting revenge on an ex-boyfriend who cheated on her. She pays some thugs to beat him up, then takes him to a cafe to console him, while the thugs trash his apartment and scratch his vinyl records, while she puts laxatives in his coffee so he gets diarrhea.
Later he has to come round to her house to use the bathroom as his has been blocked by the thugs, and Lily laughs at him behind his back while pretending to console him. The female thug in the video is played by performer/dancer/singer Tanya Billey, who attended the esteemed BRIT school of performing arts. The video finishes with Lily walking down the street smiling while the ex-boyfriend is DJing in a nightclub only to find that all his vinyl records have been scratched. Lily commented in an interview that the video was banned on MTV because it contained mugging. "I got really offended when my single, Smile, got banned from MTV in the U.K. because it had the word fuck in it!". It also has a profanity in its first verse; the offending lyric 'But you were fucking that girl next door' is censored in some releases, but present in others.