Ghajin was first started with Ajith and Asin as Mirattal, with NIC Arts bankrolling the film, and Yuvan supposed to score the music. The film even went on floors and shoot happened for a few days.
Shriya Saran was first signed to play the character of a medical student. But the role later went to Nayanthara.Prakashraj was cast as the film's antagonist, but when the lead changed, he was replaced by Pradeep Rawat because of date issues.The film's title is a reference to the tenth-century sultan Mahmud of Ghazni.The film takes inspiration from the 2000 film Memento and the 1951 film Happy Go LovelyAnil Kapoor revealed that Christopher Nolan was upset that the Ghajini team didn't give him any credits or compensation for the remake. However, the crew later met Nolan and sorted the issue out.Ghajini's storyline is similar to/based on, 1998's T.N.Nagabharana's Kannada movie 'Suthradara'. Starring Raghavendra Rajkumar & Nivedita JainMurugadoss later revealed in an interview that he had narrated the script of Ghajini to 12 actors but none of them agreed. Surya was apparently the 13th actor, who heard the script.According to ARM, Asin 's character in the film was named Kalpana after the late Indian astronaut Kalpana Chawla.Suriya apparently modelled his character of Sanjay Ramasamy on the renowned garment exporter, Tagore Bakshani.To prepare for the role, Suriya met with amnesic patients. He observed how they behave and react. He also video taped various patients and repeatedly watched them, for the character nuances.Two songs for the film - Suttum Vizhi and Oru Maalai - were shot in Switzerland with costumes brought in from Paris for the shootingARM later claimed in an interview that he saw Memento only after finishing the film's script.'I heard about Memento and the concept really fascinated me. I wrote my own version of the conflict, and later watched Memento. I found it very different from what I had written,' ARM said.Several comical scenes in the film are similar to Happy Go Lovely (1951).The scene where Kalpana (Asin) helps a blind man to cross the road is similar to the French film Amélie.Harris Jayaraj received his third Tamil Nadu State Film Award for Best Music Director and was nominated for the Filmfare Award for Best Music Director.Regarding the song Suttum Vizhi, Harris said that when Murugadoss narrated him the situation in which the hero is full of admiration for the heroine's attitude and compassion and he dreams of her.Initially, Harris conceived a peppy song in the place of the Suttum Vizhi, but after hours of discussion, he decided on a melodious tune.It was Suriya's idea to play the character of Sanjay Ramasamy as left-handed.Suriya tonsured his head to play the lead role, so he had to use a hair piece in the flash back scenes.Ghajini was censored with a 'U/A' by Central Board of Film Certification, with few minor cuts.Pradeep Rawat, who was also the costar of Aamir Khan Productions' Lagaan, asked Aamir to watch Ghajini. Aamir was very impressed and wanted to remake the film immediately.AR Murugadoss was approached to remake Ghajini in Telugu, but he declined saying he can never recreate the magic. However, when Aamir Khan requested him to adapt it in Hindi, he accepted his offer.The mobile phone number imprinted on Suriya's body shown in Ghajini turned out to be a real phone number used by a woman. After the movie was released she got lots of calls.It was Aamir Khan's strong decision to retain Asin in the Hindi version. The producers, however, were not interested in casting South heroines. Their choice to play Kalpana was Priyanka Chopra.According to Aamir Khan in 2008, the only Tamil movie that he has seen apart from Ghajini is Kamal Haasan starer Nayakan (1987).The climax of the film was rewritten for the Hindi adaptation, as ARM, in his own words, wasn't 'entirely satisfied with the Tamil version's ending.'According to Aamir, the things that excited him about Ghajini were the core conflict and the love angle. When he was hesitant to do the remake, it was Suriya who convinced him to take up the project.Suriya apparently worked with Aamir for a couple of months for improving on the character's nuances.The film was widely publicized using Suriya's six-pack abs and the intriguing tattoos on his torso.After the release of the Hindi version of Ghajini, Van Heusen launched a line of clothing based on the movie and named it 'The Ghajini Collection'.The song X machi was included in the movie at the last moment, to cash in on the popularity of Nayanthara,Suriya apparently went on a 5-hour workout regime for 6 months and followed a proportionate balanced diet in preparation for his role.Asin, Riyaz Khan and Pradeep Singh Rawat were the only cast members who reprised their roles in the Hindi version. Also some of the extras artists and stunt players remained the same.While Aamir Khan played Suriya's Sanjay Ramasamy character in the Hindi version, Surya dubbed Aamir in the Tamil version of Taare Zameen Par.During the production stages, the tonsured wounded head shot of Suriya's new appearance was released. That made many fans try the 'new hairstyle' and named it as the 'Ghajini cut'.Ghajini became the third highest grossing Tamil film of 2005. Ghajini, together with Chandramukhi and Anniyan, earned three times than the total cost.The Hindi version of Ghajini was the first Hindi movie ever to cross 100 crore. It also started the trend of the prestigious '100 crore ' club.The Telugu-dubbed version of Ghajini did better business than straight Telugu films.The film's success earned Suriya a fan following in AP.Here are few rare snaps from the movie.