Khanjar is an old Hindi movie released in 1980 produced and directed by Atmaram. This action thriller casts Navin Nischol Reena Roy, Suresh Oberoi, Amjad Khan, Jankidas, Jayshree T., Jeevan, K. N. Singh, Mehmood, Murad, Reeta Bhaduri, Sajjan, Shekhar Kapur.

Prakash (Navin Nischol), a librarian, lives with his daughter. One day, his friend and private detective Captain Usman (Suresh Oberoi) visits him and gives him a diary along with a dagger (Khanjar) to safeguard them. He also informs about their importance for a case under his investigation and threatens by some gangsters about them. Soon after this, Prakash learns that Usman is murdered. He also receives a call from a stranger enquiring about Usman's diary and the dagger. Meanwhile, a smart girl named Preeti (Reena Roy) starts to flirt and get closer to him to know about the diary and the dagger. Prakash notices her acts, illustrates to the police the story of Usman's diary, the dagger, his murder and Preeti's attempts for them. They instruct him to follow her to learn about the gangsters she works with. Upon his insistence, Preeti informs about her activities under the instructions of Prince (Amjad Khan). Soon Prince learns about her behaviour and kills her. After few days, his brother-in-law Ramesh (Shekhar Kapur), married to his younger sister Jyothi (Rita Bhaduri), is also found murdered. Disturbed by these mysterious murders leading to the dagger, Prakash and his magician friends Jagat (Mehmood) and Rasvanti (Jashree T.) visit an old town Udaigarh, famous for Swamiji (Amjad Khan). One mystery leads to a deeper mystery and a series of thrilling events unravel the mystery of the khanjar.