The Little Iliad is one of the better-attested epics in the Epic Cycle: nearly thirty lines of the original text survive. Nevertheless, we are almost entirely dependent on a summary of the Cyclic epics contained in the Chrestomatheia (see also chrestomathy) attributed to an unknown "Proclus" (possibly to be identified with the 2nd-century CE grammarian Eutychius Proclus). Numerous other references give indications of the poem's storyline.

The poem, "a fast-paced episodic epic with a lot of ground to cover"—^[1] which opened it to Aristotle's criticism, that it had more plot than an epic should have—^[2] opens with the judgment of Achilles' arms, which are to be awarded to the greatest Greek hero: the contest is between Ajax and Odysseus, who recovered Achilles' body in battle. With the help of Athena, the arms are awarded to Odysseus, and Ajax goes insane and attacks the Achaeans' herd. Later, in shame, he commits suicide, and is buried without full heroic honours, in a coffin rather than cremated on a funeral pyre, "because of the anger of the king", Agamemnon.^[3]

Calchas, the Greek prophet, prophecies that the city of Troy will not fall unless the Greeks recover the arrows of Heracles from the hero Philoctetes, who was left behind on Lemnos when he was bit by a poisonous snake. In accordance with this prophecy, Odysseus and Diomedes go to Lemnos to bring back Philoctetes, who is healed of his wound by Machaon. Philoctetes then fights Paris in single combat and kills him. After Paris' death, his wife Helen is fought over by Helenus and Deiphobus, but Deiphobus wins and marries her. The defeated Helenus angrily abandons Troy in spite and moves to Mount Ida.

Odysseus, who is a recurrent figure of interest in the Little Iliad,^[4] ambushes the Trojan prophet Helenus and captures him; Helenus then reveals three new prophecies concerning the preconditions for the Greeks' conquest of Troy, notably, that the city will not fall while it harbours the Palladium. The other two conditions are that the bones of Pelops are recovered from Pisa, a rival of Elis, and that Neoptolemus, son of Achilles, is brought into the war.

While a ship of Mycenaeans sail to Pisa to bring back the bones of Pelops, Odysseus brings Achilles' son Neoptolemus to Troy, gives him Achilles' armor, and Achilles' ghost appears to him. When the Trojan ally Eurypylus dominates the field in battle, Neoptolemus kills him.

Odysseus and Diomedes go into Troy disguised as beggars, where Helen recognises them but keeps their secret; they return safely with the Palladium, killing some Trojans on the way.

On the goddess Athena's initiative, the Greek warrior Epeus builds the wooden horse, and the Greeks place their best warriors inside it, burn their camp, and withdraw to the nearby island Tenedos. The Trojans, believing that the Greeks have departed for good, breach a section of their city wall to bring the horse inside, and celebrate their apparent victory.

The emergence of the heroes from the horse, and the Greeks' destruction of Troy, seem not to be recounted in the Little Iliad, but are left for the Iliou persis. Nonetheless, a substantial fragment which is securely attributed to the Little Iliad describes how Neoptolemus takes Hector's wife Andromache captive while Odysseus kills Hector's baby son, Astyanax, by throwing him from the walls of the city.^[5]