Kamen was approached by Columbia Pictures to compose a film similar to Avildsen’s previous success Rocky (1976), after signing the director. Kamen drew inspiration from his own life when writing the film. As a result, he maintained strong opinions regarding cast, and petitioned heavily for Morita’s inclusion. Preparations for the film began immediately after the final edit of the script was complete, and casting took place between April and June 1983. Principal photography began on October 31, 1983, in Los Angeles, and completed by December 16, 1983. The film was Macchio’s second major film role following The Outsiders (1983).

The Karate Kid was theatrically released in the United States on June 22, 1984. The film received mostly positive reviews from critics, many of whom praised the action sequences, writing, themes, performances, and music. The film was also a commercial success, grossing over $130 million worldwide, making it one of the highest-grossing films of 1984 and Hollywood’s biggest sleeper hit of the year. The film revitalized the acting career of Morita, who was previously known mostly for comedic roles, and earned him a nomination for the Academy Award for Best Supporting Actor. The film subsequently launched a media franchise and is credited for popularizing karate in the United States.