Creator Liz Tigelaar came up with the idea for the show in 2007 and developed it with director Gary Fleder, who pitched it to ABC Studios before it was sold to The CW.

After The CW ordered the show to pilot in September 2008, ABC dropped the project for financial reasons, and it was subsequently picked up by CBS Television Studios.

The series went through several title changes: it was originally announced as Light Years (since Lux's name means Light), then changed to LUX after Tigelaar felt the title 'tested way too sci-fi,' then briefly promoted as Parental Discretion Advised, before settling on Life UneXpected and finally Life Unexpected.

Although the show is set in Portland, Oregon, most filming took place in Vancouver, British Columbia, with only exterior shots done in actual Portland locations like its bridges, the MAX Lightrail, China Town Arch, and Union Station.

Scenes of Westmonte High were filmed at Sutherland Secondary School in North Vancouver and H. J. Cambie Secondary School in Richmond, while the exterior of Baze's bar was located on Granville Island and the Ironworks Building in Vancouver.

The CW aired a crossover event on October 12, 2010, where One Tree Hill characters Haley James Scott and Mia Catalano traveled to Portland to perform at a music festival hosted by K-100, aiming to boost Life Unexpected's ratings by attracting One Tree Hill viewers.

The crossover episode 'Music Faced' featured musical guests Sarah McLachlan, Ben Lee, and Rain Perry, whose song 'Beautiful Tree' serves as the series' opening theme.

Despite mostly positive reviews comparing it favorably to Gilmore Girls and Everwood, the show struggled in the ratings; The CW declined to order the back nine episodes of season two, and creator Liz Tigelaar announced the cancellation via Twitter on December 6, 2010.