Dada Sahib movie tells the story of Dada Mohammed Sahib (Mammootty) popularly called Dadasahib, who is an old freedom fighter, and his son Abubacker ( Mammootty-double role) who is a former subeidar in the army. Abubacker is the brave son of a brave father, cannot help himself from reacting when he finds some terrorist activities and arms racket taking place in his own town Thaliyoor.
But finally he finds himself being arrested on charges of espionage, treason and terrorist activity and the court too gives its final verdict-the death sentence. The President too rejects his plea and finally the sentence is carried out.
It is after this that the story takes a new turn and a battle ensues between good and the evil forces.