Earlier, the movie was titled as Robot but Shankar could not continue with the English title due to the present tax exemption of the state government. So, some other alternative titles were suggested such as Iyandhiran or Iyandhira. Later it was confirmed that the title of the movie would be Endhiran.
There was a lot of confusion regarding the casting of the film. In July 2007, Shahrukh Khan was signed as the male lead and the producer of the film. But later in October 2007, both Shahrukh and Shankar called off the project due their personal conflicts with the script. Talks were going on to sign either Ajith Kumar or Aamir Khan to do the film but in January 2008, Rajinikanth was roped in.
Several heroines including Priyanka Chopra, Deepika Padukone, Asin Thottumkal, Trisha Krishnan, Shreya Saran, Priyamani and Nayantara were approached for the female lead. But finally it was Aishwarya Bachchan, who bagged a role in the film with a huge fee of 6 crores.
Danny Denzongpa was signed for the lead antagonist and comedians like Santhanam and Karunas were signed for some cameo roles. Manoj Bharatiraja, son of the noted film-maker Bharatiraja is the assistant director. Manish Malhotra and Mary E Vogt have handaled the costumes. Music is composed by the maestro A.R.Rahaman. Stan Winston Studios will be doing the animatronics and the industrial light and Magic will be working on the visual and the special effects of the film.
Sun Pictures has bought the film rights from Eros International for 165 crores. Talks are going on with the HBO to release the film in the West with English subtitle version. The movie will be releasing in 14 July 2010.