Diana Barrie (Dame Maggie Smith) says that she wishes David Niven could accept her award for her because he would be witty and charming. In the play on which the movie is based, she says Michael Caine, but it was changed when Caine was cast as her husband.
This film version had the luxury over any stage production, by being able to be filmed at the real-life Beverly Hills Hotel. The movie was shot extensively inside, and on the grounds of the hotel. Today, the hotel's inside looks rather different, having been renovated for a whopping 150 million dollars. Today, a very strict no-filming policy is being enforced by the management, sparing its camera-shy celebrity guests, of any media hassle.
The suites, lobby, entrance, and polo lounge were not filmed at the Beverly Hills Hotel, but were recreated on studio soundstages to allow flexibility in shooting with removable walls. The lobby, entrance, and polo lounge set, measuring 6,176 square feet, was recreated on one massive soundstage at the Burbank Studios' Columbia Ranch. The hotel rooms and suites were shot on Stage 4 of the Burbank Studios. However, tennis court, and swimming-pool scenes, were shot at the real-life hotel.
The production notes for this film suggested the following promotional ideas and marketing concepts for the picture to cinemas showing the movie: "Contact the manager of your town's most luxurious hotel and tell him about the inspired entertainment in CALIFORNIA SUITE. In exchange for promotional support, arrange for the hotel to rename its most opulent suite the CALIFORNIA SUITE. Then provide the hotel with theatre passes to offer to the first patrons who stay in these glamorous accommodations. As a twist on the idea, you might suggest that a series of rooms be rechristened in honor of the stars of CALIFORNIA SUITE. For example, the Jane Fonda Suite, the Walter Matthau Suite, the Bill Cosby Suite, etc. The designated rooms might be decorated with your one sheets and pictures of the chosen stars, and the hotel would then be expected to advertise the tie-in by mounting an eye-catching lobby display that links their 'California Suite' to yours".
One of the film's stars, actress-writer-director Elaine May, previously directed another Neil Simon written film, The Heartbreak Kid (1972), but did not appear in it. Also a writer, May though never worked as a screenwriter on one of Simon's works.
In the opening credits, famous 70s artworks of British artist David Hockney are featured. The painting before Elaine May's name is entitled "Portrait of an Artist (Pool with two figures), 1972" and features a swimming pool with the Hollywood hills in the backdrop. The "two figures", both male, one swimming and the other standing over watching have been mysteriously edited out of the picture for some unknown reason.
The film's four segments, the same as in the source play, were titled: "Visitors from New York", "Visitors from London", "Visitors from Philadelphia" and "Visitors from Chicago". Herbert Ross once said, it was like filming four movies: "It was like making four films in one. It was like the play, in that we shot the four stories separately. But in the finished film, the episodes are edited together so that the action cuts back and forth between the episodes".
When Herbert Ross attended the 1978 Academy Awards, he directed the arrivals sequence for this picture at the actual event. Coincidentally, Ross had two films in contention on the night, The Turning Point (1977) (eleven nominations) for which he was nominated for both Best Director and Best Picture (Ross won neither) and The Goodbye Girl (1977) (five nominations), another film written by Neil Simon which Ross had directed but was not Oscar nominated for. Ross once said: "It was so bizarre, the whole thing. I was glad to be working on the California Suite (1978) scenes. They kept my mind off the doom I knew I was going to follow. It was eerie".
The original stage production of "California Suite" by Neil Simon, opened on April 2, 1976 at the Ahmanson Theatre in Los Angeles, and ran until June 5, 1976. The Broadway production of "California Suite" opened at the Eugene O'Neill Theatre on June 10, 1976, and ran for 445 performances, until July 2, 1977.
The room number of the suite in the film's source play was Suite No. 203-04 in the Beverly Hills Hotel. The film features the characters in four different hotel suites as the action cuts between the four episodes which in the play were set in the one hotel suite at different times, one per act.
The character name of Diana Nichols was changed from the play to Diana Barrie (played by Dame Maggie Smith) for the movie. Similary, Sidney Nichols became Sidney Cochran (Michael Caine). Moreover, Stu Franklyn and his wife Gert and Mort Hollender and his wife Beth in the play became respectively in the movie Dr. Chauncey Gump and his wife Lola and Dr. Willis Panama and his wife Bettina.
The name of the Diana Barrie (Dame Maggie Smith) movie, for which she was Oscar nominated, and starred with James Coburn, (which is seen on the plane at the start of the film, and again referenced on a plane at the film's end), was "No Left Turns". The name of the Oscar winner of the short documentary at the Academy Awards was "The Midgets of Leipzig".
The trivia items below may give away important plot points.
Dame Maggie Smith's character, Diana Barrie, is nominated for the Best Actress Academy Award, but loses the Oscar, but Dame Maggie Smith actually won an Oscar for portraying her, an Oscar loser. Moreover, Dame Maggie Smith is the only actress to ever win an Oscar for playing an Oscar nominee/Oscar loser. Cate Blanchett would later win an Oscar for playing four-time Academy Award Winner Katharine Hepburn.
Michael Caine plays a character named Sydney Cochran, whose bi-sexuality/homosexuality is revealed to his wife in the film. Caine would also later play in another film, a bisexual, whose bi-sexuality/homosexuality is also revealed, and also named Sidney (Sidney Bruhl). This film was Deathtrap (1982).