Apart from the casting of Ajith in the dual lead role, previously played by Rajinikanth, the rest of the cast took nearly four months to finalise. The role played by Sripriya in the original was given to Nayantara in early 2007, controversially after Bollywood actress, Isha Sherwani, who had been in contention to act in the last few movies of Kumar, was paid the advance. Vishnuvardhan reported that he was pleased with Nayanthara's role in "E" and subsequently opted for her. The other lead female role in the film was initially written for Shriya Saran, but due to her contract with "Sivaji: The Boss", she refused to accept the film. Despite other actresses such as Trisha Krishnan, Reema Sen, Asin Thottumkal and Bhanu being considered, the role was eventually given to Pooja Umashankar. However, she refused the role, citing that she was reluctant to appear in a bikini, as the role required. Subsequently, Namitha was signed up for the role.