The main character in the movie Lost Weekend is Don Birnam, a charming writer who is hopelessly addicted to drinking alcohol. His writing career is adversely affected by his addiction to alcohol. He is sharing his apartment with his brother Wick in New York and has a girlfriend Helen St James who is love with him. Both his brother and girlfriend realize that his addiction is adversely affecting his life, and do everything possible to ensure that he does not drink alcohol. After they have kept him sober for ten days, they plan a weekend in the countryside so that he can get a break from his routine and remain alcohol-free.

  However, Don Birnam is so addicted to alcohol, that he manages to avoid the weekend getaway sending his brother with his girlfriend to remain alone. He then remains at home and desperately searches for money to purchase alcohol. He is willing to pawn his typewriter for money. He finally finds ten dollars which were kept for the cleaning lady and goes to his favorite bar and liquor store. There he goes on a four-day drinking binge, sharing the story of his life with anyone who listens. He is then hospitalized for some time, and when he returns home, he contemplates suicide.