Director Ravi Kumar's film also features Hollywood names Mischa Barton and Martin Sheen as well as Indian-American actor Kal Penn. Tannishtha Chatterjee too joins the cast of the film, which will hit Indian screens in December.
"I am extremely satisfied with my Hollywood debut and it's a dream come true for me," said the actor.
"I have been part of the industry for so long and I have played comedy roles, supporting roles, and lead roles, but when you get such a project, you feel satisfied as an actor," added Rajpal, who featured in films like "Main Madhuri Dixit Banna Chahti Hoon!" and "Main, Meri Patni... Aur Woh!".
"Bhopal - A Prayer For Rain" is based on true events of 1984 when a toxic gas leak from the Union Carbide Corporation's pesticide plant in the Madhya Pradesh capital killed and maimed thousands of people.
"I am playing the lead in it. I am playing actress Tannishtha's husband. It will release in India on Dec 5 and Nov 7 in the US," he said.