Diana Barrie (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 actually be filmed at the real life and famous Beverly Hills Hotel. The movie 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. Today a very strict no-filming policy is being enforced by the management, sparing its camera-shy celebrity guests of any media hassle.
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 original production of the "California Suite" by Neil Simon, a play in two acts, opened on 2nd April 1976 at the Ahmanson Theatre in Los Angeles and ran until 5th June 1976. The Broadway production of "California Suite" opened at the Eugene O'Neill Theatre on 10th June 1976 and ran for 445 performances until 2nd July 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 suites, lobby, entrance and polo lounge were not filmed at the Beverly Hills Hotel but were recreated on studio sound-stages 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 sound stage 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.
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) (11 nominations) for which he was nominated for both Best Director and Best Picture (Ross won neither) and The Goodbye Girl (1977) (5 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".
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.
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". Director 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".
The character name of Diana Nichols was changed from the play to Diana Barrie (played by 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 (Maggie Smith) movie that she was Oscar nominated for and starred in 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 picture is considered similar to the earlier Neil Simon written film Plaza Suite (1971) as they both involve comedy and drama centering around guests staying in a luxury hotel suite. The movie was made and released about seven years after Plaza Suite (1971) .
"CALIFORNIA SUITE, written by [Neil] Simon from his own Broadway smash, is set in the chic confines of the Beverly Hills Hotel, where an assortment of funny, troubled, zany, lovable, laugh provoking travelers have signed the register . . . The Beverly Hills Hotel is world-famous, and it is the natural choice of temporary residence for five diverse couples who have come to Los Angeles for other reasons but find there a deeper and fuller understanding of themselves, their mates and their situations in life. They all are people with personal problems; they also are people in love" stated the picture's production notes.
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".
The trivia items below may give away important plot points.
Maggie Smith's character, Diana Barrie, is nominated for the Best Actress Academy Award but loses the Oscar, but Maggie Smith actually won an Oscar for portraying her, an Oscar loser. Moreover, 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 called 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 [SPOILER ALERT] --- Deathtrap (1982).