Karan Arjun is about faith and reincarnation. Durga (Rakhee) sons, Karan (Salman Khan) and Arjun (Shahrukh Khan) are murdered by Durjan Singh (Amrish Puri). When Durga's pleas to bring Karan Arjun back to life are heard by the Goddess Kali, the two brothers are reborn in different families.
Karan as Ajay, grows up to be a boxer and goes to work for Saxena (Ranjeet), Durjan Singh's partner in crime. Arjun as Vijay, grows up to work with horses and falls in love with Sonia (Kajol), Saxena's daughter and Durjan Singh's soon to be daughter-in-law. By divine intervention Ajay and Vijay realize they are Karan Arjun, and return to their mother Durga to take revenge upon Durjan Singh.
Will Karan amd Arjun succeed this time in defeating Durjan Singh?