The opening crawl reveals that the Galactic Empire has pursued the Rebel Alliance across the galaxy, forcing them to establish a secret base on the remote ice planet Hoth. Dark Lord of the Sith Darth Vader (David Prowse/voice: James Earl Jones) sends robotic probes in search of the base and its commander, Luke Skywalker (Mark Hamill). While Luke is patrolling near the base, he's knocked unconscious by an indigenous predator, the Wampa. Back at the base, the smuggler-pilot Han Solo (Harrison Ford) announces his intention to leave the Rebels and pay the debt he owes to the gangster Jabba the Hutt, much to the displeasure of Princess Leia (Carrie Fisher). After Han discovers that Luke has not returned from patrol, he delays his departure and leaves the base to search for him. Luke escapes the Wampa's lair but is overcome by the cold. He sees an apparition of his late mentor, Jedi Master Obi-Wan Kenobi (Alec Guiness), who instructs him to receive training from Jedi Master Yoda (voice: Frank Oz) on the planet Dagobah. Han finds Luke and gives him shelter until they're rescued the following morning.

When ground scans detect an object outside the base perimeter, Han and Chewy investigate, and find an Imperial probe droid that transmits the location of the Rebel base to the Imperial fleet before firing upon Chewy and being destroyed. On the command ship of Darth Vader the droid's transmission is picked up by Captain Piett, but his superior, Admiral Ozzel, dismisses the message until Vader sees the transmission and realizes it is the Rebel base. He overrules Ozzel and orders the Fleet to the Hoth system.

Later, as the Fleet emerges from trans-star warp, Vader is informed by his infantry commander, General Viers, that the Rebels have set up infantry trenches and an energy shield to protect them from the Empire's orbital bombardment. Ordering Viers to launch a surface attack, Vader is furious that Ozzel has clumsily given away surprise, and he communicates this displeasure to Captain Piett as he promotes him on the spot to Admiral while Ozzel is given Vader's own fatal brand of reprimand.

The Imperial forces land their ground assault walkers beyond the energy shield and Luke leads his squadron of flying speeders into battle. However, the Imperial forces eventually overpower the Rebels and destroy the generator powering the energy shield, capturing the Rebel base. Han Solo, Princess Leia, Chewbacca (Peter Mayhew), and their droid C-3PO (Anthony Daniels) flee on board the Millennium Falcon. However, the Falcon hyperdrive is damaged and it cannot escape the Imperial blockade in space. During the confusion, they enter an asteroid field; Han Solo pilots the Millennium Falcon deeper into the field, eventually landing inside an asteroid crater. Meanwhile, Luke and his astro droid R2-D2 (Kenny Baker) escape Hoth in Luke's X-wing fighter. After a crash landing on Dagobah, Luke meets a wizened, green little creature who reveals himself to be Yoda. Meanwhile,