Criminal is action thriller based movie in which, Dr. Ajay Kumar (Akkineni Nagarjuna) cancels his U.S. immigration and instead sets out to work a plan to open a hospital that will be accessible to people who cannot afford treatment in regular hospitals, called "Amma People's Hospital".
This draws quite an attention, and he becomes popular, especially with two young women, Shweta (Manisha Koirala) and Sub-Inspector Ramya (Ramya Krishna). He falls in love with Shweta and both get married, breaking Ramya's heart in the process. Shortly thereafter Shweta gets pregnant, much to their delight.
Then one night, Ramya gets a distress call from Shweta, who calls the police for help as she is being attacked, and names the attacker as "Ajay". The police arrive to find her dead body and arrest Ajay for murder. It seems that Ajay's motive for killing Shweta was for money, as Shweta is a wealthy heiress.
Ajay is convicted and sentenced to death. While being transported to prison, the police van meets with an accident and Ajay escapes. The police launch a manhunt for him, but are unable to catch him. Ajay secretly meets with Ramya and tells her that he did not kill Shweta, and he wants her help to catch the real killer. Will Ramya believe him, or is he just making up a story to justify his escape from facing the death penalty?