Gilbert Grape is a small-town young man with a lot of responsibility. Chief among his concerns are his mother, who is so overweight that she can't leave the house, and his mentally impaired younger brother, Arnie, who has a knack for finding trouble. Settled into a job at a grocery store and an ongoing affair with local woman Betty Carver, Gilbert finally has his life shaken up by the free-spirited Becky.

An aspiring musician is released from prison to find that a song he had written while locked up has been stolen and made into a hit record by a country music superstar. When his confrontation with the star takes a violent turn the ex-con has to go back on the run, but he finds an unexpected ally in a shrewd background singer with a plan to turn the tables in his favor.