The poem opens with the sage Valmiki asking the heavenly seer Narad whether any man alive is virtuous, heroic, grateful, and true to his word. Narad answers with Rama, eldest son of King Dasaratha of Ayodhya, and recites the story that Valmiki then shapes into verse. Rama grows up obedient and self-controlled, guards forest hermits and their rites from demons, and wins Sita, daughter of King Janak, by lifting and breaking the great bow that no other suitor could bend.
On the eve of Rama's consecration as heir, Queen Kaikeyi, worked on by her maid Manthara, claims two boons the king granted her long ago: her son Bharat is to be crowned, and Rama banished to the forest for fourteen years. Bound by his word, Dasaratha can neither refuse nor speak. Rama accepts the sentence calmly, ascribes it to fate rather than to any person's malice, and leaves the same day dressed in bark. Sita insists that a wife's one refuge is her husband and walks out beside him, as does his brother Lakshman. The old king dies of grief soon after.
Bharat returns to find his father dead and his brother exiled, rejects the throne his mother won, and travels to the forest to beg Rama home. Rama will not break the promise, even when the sage Javali urges that vows made to the dead are empty; truth, he replies, upholds kings and the world itself. So Bharat carries Rama's sandals back, sets them on the throne, and governs as a steward from a village. The exiles move deeper into the Dandak wilds, where Rama protects the hermits, and where Lakshman, at Rama's word, maims the demoness Surpanakha after she attacks Sita. Her shame reaches her brother Ravan, king of the giants of Lanka.
Ravan forces the reluctant Maricha to take the form of a wondrous golden deer. Sita begs Rama to capture it, the dying fiend mimics Rama's voice to draw Lakshman away too, and Ravan carries Sita through the air to Lanka, cutting down the aged vulture Jatayus who tries to save her. Searching for her, Rama makes a pact with Sugriva, an exiled Vanar king, kills his oppressor Bali with a single arrow, and gains the service of the Vanar hosts. Hanuman, the Wind-God's son, leaps two hundred leagues of sea, finds Sita captive in Ravan's Asoka grove and still scorning her captor's suit, gives her Rama's ring as a token, burns the city, and returns with word of her.
The Vanars bridge the sea, and Ravan's righteous brother Vibhishan, disgraced for honest counsel, is received under Rama's vow never to forsake a suppliant. The long battle costs both sides their champions, among them the giant Kumbhakarna and Ravan's son Indrajit, until Rama's arrow cleaves Ravan's heart. He grants his fallen enemy funeral rites, since hatred ends at death. Sita, doubted before the host, passes through fire; the Fire-God returns her unharmed, the gods proclaim Rama as Vishnu in human form, and husband and wife are reconciled. The exile complete, Rama flies home by the magic car, is consecrated king, and begins a reign the poem describes as a golden age in which no widow mourned and no harvest failed.