In 1950, Al & Mary Slonaker unveiled the National Roadster Show at the Oakland Exposition Hall in Oakland, California. The show was a 10-day event and attracted thousands of hot rod enthusiasts. In 1962, the show was renamed the Grand National Roadster Show. In 1967, the show moved to the Oakland Coliseum, where it stayed until 1997. The show through the years was unofficially known as the Oakland Roadster Show by many of the fans. Today, it is affectionately known as the GNRS.

In 2004, the Grand National Roadster Show moved to Southern California to its current home at the Fairplex in Pomona. The show has grown to take over all eight buildings and the surrounding outside grounds.

In 2024, the GNRS will celebrate its 75th year as the longest-running indoor car show in the world. Rod Shows is the current owner of the Grand National Roadster Show.