Operation: Mindcrime is Queensrÿche's third full-length album, which was released on May 3, 1988. It is a concept album about a man becoming disillusioned with American society, and joining in a conspiratorial plot to assassinate its corrupt leaders, with spoken dialogue between songs that advances the story and ties the songs together. The album is generally considered to be the first, and still one of the most important and popular, progressive metal recordings. In January 1989, it ranked #34 on Kerrang! magazine's "100 Greatest Heavy Metal Albums Of All Time".

During the tour promoting the 1990 album Empire, Operation: Mindcrime was performed in its entirety. The stage show featured video, animation and guest singer Pamela Moore as Sister Mary. This live show was successful enough that the band released it as a box set called Operation: LIVEcrime. The story was initially explored in a series of video clips for MTV in the 1989 VHS video, Video: Mindcrime.

In the United States, the album was certified gold a year after its release and was certified platinum in 1991.

In 2003, a 24-bit remastered version of Operation: Mindcrime was released that included live versions of "The Mission" and "My Empty Room" as bonus tracks.

In 2006, EMI released a deluxe Operation: Mindcrime box set that included the 2003 remaster, as well as an audio disc of a November 15 1990 Hammersmith Odeon concert, with the band performing the entire album, and a bonus DVD containing Video: Mindcrime and bonus clips.

The sequel, Operation: Mindcrime II, was released on April 4, 2006, with Ronnie James Dio taking over the role of "Dr. X". The subsequent tour consisted of the band performing both Operation: Mindcrime and its sequel in their entireties, back-to-back, with actors, props, an elaborate stage set, and a video screen. The live act from that tour also definitively answered the long-asked question, "Who killed Mary?"