While developing the character, Mike Myers originally didn't want to share the limelight with Dana Carvey. Myers had originally created Wayne as a solo character while performing with Second City. But when Mike joined Saturday Night Live, in order to get the sketch off the ground, he needed to pair up with an already established cast member. So, the character of Garth was added for Saturday Night Live (1975).
Rob Lowe has said he discovered his "hitherto untapped gift for comedy" after meeting Mike Myers, who would later cast him in the Austin Powers sequels. The film is credited with reviving his career following the sex-tape scandal.
Mike Myers said filming was "a blur," because his father's health was dwindling at the same time. "I remember finishing the film, then I remember my dad dying," he said in an interview in 2013.
The character of Garth was barely in the original script. Dana Carvey would add more to his character in the script, only to find that Mike Myers would then take his ideas out. This caused Dana to quit the movie just weeks before shooting. He had to be convinced to come back, which he obviously did. However, Dana would return only if Mike agreed to two conditions. He wanted free reign to ad-lib on set, and to contribute to the development of his character, which Mike agreed to both.