NCIS: Los Angeles is an American Police Procedural Television show which is set in Los Angeles at the NCIS Office of Special Projects.

The Office of Special Projects (OSP) is a clandestine division of NCIS. There the highly trained NCIS Los Angeles team is charged with apprehending dangerous and elusive criminals who pose a threat to America’s security. This they do by assuming false identities, going undercover and utilising the most advanced technology. The agents put their lives on the line to bring down their targets, doing whatever is necessary to get the job done.

NCIS: Los Angeles is the first spin-off of NCIS, which itself was a spinoff of another CBS series, JAG.

Filming started in February 2009, with the characters being introduced in the two-part NCIS episode titled "Legend", the first part of which aired on April 28, 2009. This episode served as a backdoor pilot for the series, in a manner similar to the introduction of NCIS, which was introduced by way of a two-part episode of JAG.

The first episode was moderately well reviewed by critics -

Mary McNamara of the Los Angeles Times - "The crime is intriguing and multifaceted, its resolution requiring a nice balance of street smarts and lots of gunfire. But as with the original "NCIS," the emphasis is on the characters of the team... Los Angeles, meanwhile, looks fabulous, a pleasing mixture of noir and gridlock, and there's an air of stability that's comforting in these uncertain times."

David Hinckley of the New York Daily News was more critical of the show saying that although "It all adds up to an hour of decent entertainment, and there's room for enough character development to give "NCIS: Los Angeles" a personality of its own, ... a premiere episode shouldn't feel even a little like something we've already seen."

Tom Shales of The Washington Post felt that "NCIS: Los Angeles gets the job done ... It's a procedural that follows strictly the established procedure, but it has likable characters, dislikable bad guys and the occasional flabbergasting shot of L.A."

Robert Bianco of USA Today summarized it as a "serviceable hour that takes the NCIS formula—a light tone and a lot of banter wrapped around a fairly rudimentary investigatory plot—and transfers it to a special, undercover NCIS division in Los Angeles. Nothing more, but also nothing less."

The Hollywood Reporter compared the show to The A-Team with "the same lighthearted approach to life-or-death situations. Maybe the biggest change is that "NCIS: L.A." achieves its inevitably favorable outcomes with a little more intellect and a little less testosterone."

IGN stated that although "NCIS: Los Angeles doesn't exactly reinvent the police procedural... it's another above-average entry, aided by the fact that the people behind the show know what they're doing."