In 1965, Dinanath Chauhan, a village schoolmaster, stands as an outspoken critic of local underworld don Kancha Cheena and his plan to turn the village into a base for heroin smuggling. When a fabricated scandal is engineered by Kancha and the village landlord Dinkar Rao, Dinanath is lynched by the townspeople, leaving his family to struggle for survival. His young son, Vijay Deenanath Chauhan, vows to avenge his father's death, restore the family name, and punish those responsible.
Years later, in Mumbai, Vijay Deenanath Chauhan climbs the violent ladder of the underworld under the tutelage of seasoned enforcers like Hasmukh, Usman Bhai, and Anna Shetty. He begins to amass power, hardening his heart against his mother, Suhasini Chauhan, and his sister, Siksha Chauhan, even as he believes his choices are a form of justice for those he lost.
One day, he is warned by Police Commissioner M. S. Gaitonde about an assassination plot hatched by his former allies. Rather than back down, Vijay lets the attack unfold, convinced that surviving it will raise his standing. He is rescued by a compassionate coconut vendor who later becomes his ally, Krishnan Iyer MA, a man who will eventually serve as Siksha Chauhan's protector and a steadfast friend to Vijay. In the hospital, a nurse, Mary Matthew, tends to him and becomes an intimate confidante who will share his later choices and destinies.
Vijay quietly eliminates the two men who had surrendered to police—[Hasmukh] and Usman Bhai—before facing his mother’s scorn as she refuses to accept the life he has chosen. Disillusioned but not broken, he finds solace in his relationship with Mary Matthew, and their bond deepens. Meanwhile, Anna Shetty kidnaps Siksha Chauhan to draw Vijay into a trap; Krishnan tries to rescue her but fails, and Vijay arrives to finish the confrontation by killing Anna.
Romantic tension grows between Krishnan Iyer MA and Siksha Chauhan, which Suhasini Chauhan does not approve of, ultimately disowning Vijay—but she nonetheless supports her son’s moral awakening. Hurt, Vijay marries Mary Matthew and commits to reform his life in order to win his mother’s respect.
With renewed purpose, Vijay re-enters Kancha Cheena's world under the guise of a deal, regains control of the village, and arranges for the lynching of Dinkar Rao to symbolically reverse the wrongs of the past. He also calls for testimony from Laila (revealed to be Shanti, the daughter of a woman involved in Dinanath's framing) to convict Kancha, allowing the village to gradually return to Suhasini Chauhan's care.
Yet Kancha escapes custody by orchestrating further murders and kidnappings, forcing Vijay back into violence for one final showdown. In the resulting ferocious battle, Vijay defeats Kancha by hurling him into a raging fire; the fight proves too costly for him, and he dies in his mother’s arms at the ruins of their old home. In his last breath, he declares that he was never a criminal, but a son who walked the path of fire, the Agneepath, to seek justice. Suhasini forgiving him marks the ending with a quiet, mournful grace.
