Actor Robert Downey Jr. has said of this film at the Robert Downey Jnr Film Guide website: "Ron Underwood really attracted me to Heart and Souls. It's a character-driven film about sacrifice-the sacrifices people make for one another, and the sacrifice you have to make to find any semblance of bliss. And then there's Thomas whose head is spinning from the realization that these souls are real, and he's going to have to bend a little to make room for them ... Real fine, San Francisco, lots of money. Probably one of the best times in my life. Good movie ... It's a fun movie, in which I only have to wear one costume. Even my hair stays the same in the whole movie, and the only thing I had to do was act. So that was a piece of cake".
Julia's letter to John reads as follows: "John, There was so much I wanted to say to you tonight, but everything I said somehow came out all wrong. I am coming home because I want to be with you. I hope you'll give me another chance. Whatever happens, please know I will love you always. Julia"
Before she dies, Julia is seen waitressing at "The Purple Onion", a real San Francisco club where comedians such as Phyllis Diller and the Smothers Brothers (Dick Smothers and Tom Smothers) performed. When Julia's boyfriend shows up, the comedian on stage is dressed like, and performing one of the monologues of, Bob Newhart, because he is Newhart's son.
The pictured was nominated for ten Academy of Science Fiction, Fantasy & Horror Films (Saturn) Awards including Best Fantasy Film and two nominations each for Best Supporting Actor and Actress but the film only won just the one Saturn Award, for Best Actor - Robert Downey Jr..
Some of the literal English language translations of this film's foreign language titles, according to the Robert Downey Jnr Film Guide website, are: Argentina: El Amor es Eterno (Love is Eternal); Brazil: Morrendo e Aprendendo (Dying and Learning); France: Drôles de fantômes (Funny Ghosts); Germany: Vier Himmlische Freunde (Four Heavenly Friends); Israel: One More Chance for Life (English translation); Italy: Quattro Fantasmi Per Un Sogno (Four Ghosts for a Dream); Japan: When Love is Smiling (English translation); Poland: Serce i Dusze (Heart and Souls); Spain: Corazones y Almas (Heart and Souls).
Appearing uncredited as a psychiatric ward patient in this movie was American actress Chloe Webb who ironically had also appeared uncredited in another earlier poltergeist picture , as Elaine in Ghostbusters II (1989).
According to website Film in America, the filming location of the coach crash had "the bus dropped from Stockton Street at California down below the tunnel to Stockton at Sacramento. The Ritz Carlton Hotel at 600 Stockton Street" was visible. The IMDb gives the location as "Stockton Tunnel Southern Approach Overhang, Bush Street & Stockton Street, Downtown, San Francisco, California, USA".
This was the first movie that David Paymer was seen in after Mr. Saturday Night (1992) in which he had received an Academy Award Best Supporting Actor nomination. The film was also one of two 1993 feature films featuring Paymer which were first released in this year. The other picture was Searching for Bobby Fischer (1993).