The movie was shot and completed so quickly that by the time Robert Rodriguez was ready to ship it, the advertisements weren't finished.
The story was conceived by Robert Rodriguez's then seven-year-old son Racer Rodriguez, who receives an on-screen "Story By" credit. Max is named after Racer's middle name (Racer and Robert also provide the audio commentary for the DVD and Blu-ray together).
Taylor Lautner's martial arts skills helped him to obtain the role of Sharkboy. "When I auditioned for the film, Robert Rodriguez, the director, didn't know that I had my martial arts background, and while we there in Austin, TX he saw a DVD of me and asked me to choreograph my own fight scenes", said Lautner.
Numerous clues are visible in Max's real world: Max eats shark-themed cereal, Mr. Electricidad wears a lightning bolt tie clip, Marissa wears snowflake earrings, classroom artwork depicts a shark, volcano, and planets.
Robert Rodriguez: [fictional brand names] While Max is on the dock before he runs into Sharkboy you can see a fast food bag for "Big Kahuna Burgers" a fictional burger joint, also used in films of Rodriguez' friend Quentin Tarantino.