Leonardo DiCaprio's father George DiCaprio portrays the man who sells Gary a waterbed in the film. George was a well-known figure in the Southern California underground art scene during the era depicted in the film.
Alana's family is played by her real-life family members. She and her sisters are the members of Haim, a Grammy-nominated rock band. Paul Thomas Anderson previously directed a number of music videos for Haim, and when he was a child, his elementary art school teacher was Donna Haim, the mother of the girls. This film was partly inspired by a crush he had on her when he was her student.
Alana Kane's father is played by Alana Haim's real-life father, Moti Haim. According to director Paul Thomas Anderson, all of Moti Haim's lines were improvised. The scene in which Alana comes home and Moti exclaims, "What the fuck!" is a first take.
As is mentioned in the film, pinball was banned in Los Angeles from 1939 to 1973 on the grounds that it was legally a form of gambling.
Debut of Cooper Hoffman. He is the son of the late Philip Seymour Hoffman, frequent collaborator with Paul Thomas Anderson.
John C. Reilly: playing Fred Gwynne/Herman Munster. Reilly is a collaborator in Paul Thomas Anderson's films. This is his fourth work with Anderson after Hard Eight (1996), Boogie Nights (1997) and Magnolia (1999).