The Vishnu Purana is framed as a dialogue. The pupil Maitreya asks his teacher Parasara how the universe came into being, how it is sustained, and how it will end, along with the genealogies of gods and kings and the duties men should keep. Parasara answers that everything has sprung from Vishnu and is established in him, and the rest of the work expands that single claim across six books.
The first book is cosmogony. Before creation there was neither day nor night, only the unmanifest cause. From Vishnu come Pradhana, the chief material principle, and Purusha, spirit, set in motion by time. The book then narrates the boar incarnation, in which Vishnu lifts the drowned Earth from the deep, and follows the early lines of patriarchs, the origin of the castes, and legends such as the boy Dhruva and the devout Prahlada, whose faith holds even against a hostile father.
The middle books turn to the shape and history of the world. The second describes the Earth itself: its concentric continents and seas, the land of Bharata, the regions below, the hells, and the spheres and chariots of the sun and moon, with a measure of time that runs from the blink of an eye up to the immense day of Brahma. The third lays out the successive Manus who govern world-ages, the division of the Vedas, and a long account of the duties of caste and stage of life, of rites for ancestors, and of right conduct for a householder.
The fourth and fifth books are genealogy and story. The fourth traces the solar and lunar dynasties of kings from their divine origin down through famous names to the rulers of the present age and even those foretold to come. The fifth is given almost entirely to Krishna: his birth in danger, his boyhood among the cowherds, his lifting of Mount Govardhana, the defeat of the tyrant Kansa, and the events that lead at last to the passing of his own people.
The sixth and final book returns to the question of endings. It describes the dissolution of the world and the decline of the Kali age, when caste, study, and marriage rules fall away and men grow short-lived and selfish. Yet it also calls the Kali age fortunate, because in it merit that once took years of penance can be won by simply reciting the names of the lord. The work closes on liberation: the nature of ignorance, the practice of yoga, and the knowledge of the supreme spirit that frees a soul from rebirth.