Grey's Anatomy is an American medical drama television series. It follows the lives of interns, residents and their mentors in the fictional Seattle Grace Mercy West Hospital (formerly Seattle Grace Hospital) in Seattle, Washington. The pilot episode, "A Hard Day's Night" premiered on March 27, 2005 on ABC. Since then, five seasons have aired, and the sixth season began on September 24, 2009. It has been confirmed through a tweet on the authentic Shonda Rhimes Twitter account that the cast of Grey's Anatomy has signed on through at least eight seasons, which would keep the show on the air until at least Spring 2012. Season 6 began in the UK, on thursday 21st January 2010.

The show has attained commercial success and critical acclaim. Initially airing as a Midseason replacement for the legal drama Boston Legal it gained high viewership, with the first episode watched by 16.25 million viewers, and the first season finale attracting 22.22 million viewers. Winner of two Emmy Awards and two Golden Globe Awards, the show is one of the most watched prime time television series.