Endhiran background

After completing Nayak: The Real Hero in 2001, Shankar announced a project with Kamal Haasan and Preity Zinta titled Robo, to be produced by the now-defunct production company Media Dreams. Despite, announcing the project, due to a lack of backing, the project was cancelled and Shankar began work on Boys. In 2005, Shankar made another project, Anniyan, this was mistaken to be the renamed title for Robot.

In early 2007, Shankar stated that his next project would be produced by his production house, S Pictures for 3 months. Several websites claimed that he was set to take his maiden Telugu language film with Chiranjeevi, while others claimed that it was set to be with Mahesh Babu. Tabloid gossip columns reported that Ajith Kumar was considered for the film. Finally, in July 2007, Shahrukh Khan was signed on to be the male lead of Robot as well as the producer of the film. However, in October 2007, Shahrukh Khan and Shankar officially called off the project due to creative differences.

After further media speculation about Aamir Khan and Hrithik Roshan being roped in, official reports surfaced in early January 2008, that Rajinikanth was finalized for the project. Later in January 2008, Ayngaran International and Eros Labs agreed to become the producers of Robot. The film was unable to keep its name, Robot, due to the English title in Tamil Nadu, where the government exempted entertainment tax to films with Tamil titles. It was confirmed in September 2008 that the film has been renamed as Enthiran. The film's storyboarding and scripting was going on as told by Shankar in two interviews. It was subsequently announced that all those who have been committed forRobot should sign an agreement accepting that they will not commit themselves to any other project for the next two years of its production, with an exemption to the female lead, Aishwarya Rai.

In December 2008, Eros Labs cited the failures of Drona and Yuvvraj for putting them under financial pressure. Soon, Ayngaran International too claimed that it was affected by the global financial crisis of 2008, forcing both production houses to transfer the project toSun Pictures who also attempted to negotiate a deal with HBO Films to release the film with English subtitles in the West, As of September 2010, the budget of the film was confirmed as 162 crore.