The story follows Mark Renton, a heroin addict living in Leith. Mark and his addict friend, Spud live off unemployment funds issued by the government. They both have different addresses in order to collect more money. Mark, Spud, Tommy, and Williamson decide to hold a heroin party where Williamson’s daughter dies while the crew is under the influence of drugs.
Begbie, who supplies drugs to the gang relapses after learning that his girlfriend has been cheating on him while he was away. Under the influence of heroin, Mark ends up sleeping with a minor. Afterward, he and his friends are caught stealing some books from the library to fund their habits. Mark is sent off to rehab.
Mark returns home months later only to find his brother Billy dead. Unable to face the hurdles in his life, Mark runs off to London where he meets up with his old friend, Kelly. The two have a brief sexual relationship which ends after Mark goes to visit his friend Davie who has contracted AIDS. Davie, with the help of his friends tracks down the man who gave him HIV, and they kill him.
Mark moves back to Leith where he and his friends start dealing drugs. The group sells sixteen thousand pounds worth of heroin the crew goes out to celebrate. Mark steals the money and flees to Amsterdam to begin a new life. He vows never to return home.