She made her film career debut with "Rehna Hai Tere Dil Mein". In this movie, she worked with R. Madhavan. Although the film did not succeed at the box office, but the music of this film was successful. After this she worked in "Deewaanapan" and "Tumko Na Bhool Paayenge". In 2005, Diya Mirza worked in Vidhu Vinod Chopra's film "Parineeta". In 2006, she again worked with Vidhu Vinod Chopra's film "Lage Raho Munna Bhai" with Sanjay Dutt. she also worked in Sonu Nigam's music video "Kajra Mohabbat Wala". After this, she had unsuccessful films like Dus Kahaniyaan, Fight Club – Members Only, Alag, Honeymoon Travels Pvt. Ltd. and Cash.