In the film, Sanjay Singhania, a powerful entrepreneur, suffers from anterograde amnesia after a violent attack on him and his fiancée Kalpana.

A. R. Rahman composed the soundtrack and musical score, while cinematography and editing were handled by Ravi K. Chandran and Anthony.

[9] Sunita, a medical student, is investigating the anterograde amnesia case of Sanjay Singhania, the chairman of Air Voice, a telecommunications company.

Sanjay, who loses his memory every 15 minutes, uses a system of photographs, notes, and tattoos on his body to recover his memory and remember his mission of avenging the murder of his fiancée Kalpana Shetty, who was killed by Ghajini Dharmatma, a kingpin and a notable socialite in Mumbai.

Arjun reads the first diary and learns that Sanjay, a successful entrepreneur, met Kalpana, a struggling model, after planning to install an advertising billboard above her apartment.

In the meantime, Sunita locates the apartment, finds Arjun tied up, beaten and bound, and learns of Sanjay's murder plot.

In the second diary, Kalpana accepts the proposal on the condition that she purchases three Ambassador cars due to a past commitment.

After some research, Sunita eventually learns Kalpana travelled to Goa, where she stumbled across and freed a group of girls from a sex trafficking ring racketeered by Ghajini.

Later that night, a constable calls Kalpana and informs her that Ghajini has set out to kill her and his henchmen are hiding inside her house.

[13] Khan was involved in the film's creative writing process, deciding what should remain from the original Tamil Ghajini and what changes should be made.

Every time I'd suggest a change in Ghajini from the original, Aamir would firmly cut it down, saying we should stick to the Tamil script.

The film stars Guy Pearce as Leonard Shelby, a former insurance fraud investigator searching for the man he believes raped and killed his wife during a burglary.

Certain concepts like writing notes behind instant Polaroid photographs and tattooing facts on his body are also similar.

"[16] The CGI opening brain sequence was inspired by the 1999 film Fight Club by David Fincher.

The film's title is a reference to Mahmud of Ghazni, the tenth-century Sultan of the Ghaznavid Empire whose name is pronounced "Ghajini" in Tamil.

Other filming locations included Bangalore, Cape Town in South Africa, the Deadpan Desert in Namibia and Mumbai.

Ghajini was also released in Norway, Germany, Denmark, Netherlands, Belgium, South Africa, Australia, New Zealand, Hong Kong and Singapore.

[21] The two-disc collector's edition DVD was manufactured by Big Home Video and distributed by international distributor, Adlabs Films Ltd. (now Reliance MediaWorks) on 13 March 2009.

It is a third-person action game consisting of five levels of play; here the player controlled the protagonist Sanjay to accomplish missions using martial arts, weapons, and artefacts.

According to Salem Chandrasekhar, the producer of the Tamil original, he had not bought the rights to remake the film in Hindi.

[31] Rajeev Masand of CNN IBN wrote "Ghajini isn't a particularly good film, but entertainment it delivers by the bucketful.

"[32] Martin D'Souza of Bollywood Trade News Network notes its flaws in the script, while praising the action sequences.

[34] Nikhat Kazmi of The Times of India praised the performance by Aamir Khan as its high point.

[36] Sukanya Verma of Rediff describes the film as "a sleek album of dark memories, which are terrifying to relive and shattering to experience".

[37] Noyon Jyoti Parasara of AOL India said, "Most comparisons often point out that a remake is not as worthy.Ghajini however succeeds when it is compared to the Tamil version directed by the same director.

[46] The film has six songs, including two remixes, composed by A. R. Rahman and with lyrics penned by Prasoon Joshi.

Bollywood Hungama wrote, "The music of Ghajini is all set to make waves way into 2009 after the Christmas release of the film.