Integrated with the architecture of the building, and one of the causes for its fame is Angkor Wat's extensive decoration, which predominantly takes the form of bas-relief friezes. The inner walls of the outer gallery bear a series of large-scale scenes mainly depicting episodes from the Hindu epics the Ramayana and the Mahabharata. Higham has called these, "the greatest known linear arrangement of stone carving".[35] From the north-west corner anti-clockwise, the western gallery shows the Battle of Lanka (from the Ramayana, in which Rama defeats Ravana) and the Battle of Kurukshetra (from the Mahabharata, showing the mutual annihilation of the Kaurava and Pandava clans). On the southern gallery follow the only historical scene, a procession of Suryavarman II, then the 32 hells and 37 heavens of Hindu mythology. Glaize writes of;

    "... those unfortunate souls who are to be thrown down to hell to suffer a refined cruelty which, at times, seems to be a little disproportionate to the severity of the crimes committed. So it is that people who have damaged others' property have their bones broken, that the glutton is cleaved in two, that rice thieves are afflicted with enormous bellies of hot iron, that those who picked the flowers in the garden of Shiva have their heads pierced with nails, and thieves are exposed to cold discomfort."[36]

On the eastern gallery is one of the most celebrated scenes, the Churning of the Sea of Milk, showing 92[37] asuras and 88 devas using the serpent Vasuki to churn the sea under Vishnu's direction (Mannikka counts only 91 asuras, and explains the asymmetrical numbers as representing the number of days from the winter solstice to the spring equinox, and from the equinox to the summer solstice).[38] It is followed by Vishnu defeating asuras (a 16th-century addition). The northern gallery shows Krishna's victory over Bana (where according to Glaize, "The workmanship is at its worst"[39]) and a battle between the Hindu gods and asuras. The north-west and south-west corner pavilions both feature much smaller-scale scenes, some unidentified but most from the Ramayana or the life of Krishna.