After college, Kothari became a model and appeared in a number of advertisement campaigns. She appeared in the music video of the remix of Chadti Jawani Meri Chaal Mastani. In 2003, she got her big break through actor Madhavan, who recommended her for an audition in his film after viewing her photographs. She made her acting debut with him in the Tamil film Jay Jay, credited as Amoga. She made her Bollywood debut in the 2005 film Sarkar and then later that same year appeared in James, directed by Ram Gopal Varma and Rohit Jugraj respectively. James turned her into a sex symbol overnight. She then went on to do The Killer with Emraan Hashmi. Since then she had appeared in less significant films and roles. She was regularly seen in Ram Gopal Varma's films like Shiva, Darna Zaroori Hai, Aag, in which she played a tapori called Ghungroo, Darling and Agyaat and also his productions like Go and Stalker. Most of the films were unsuccessful. She made her Sandalwood debut with Raaj-the Showman opposite Puneet Rajkumar in 2009 and later did a supporting role in Dandupalya. She was seen in a Telugu film with Balakrishna, Okka Magadu which also bombed and also acted in a film titled Hari Om.