The film
- Actor-Inspired Element: Peter Ustinov designed Poirot's bathing suit.
- Box Office Bomb: Only pulled in about $6 million in the US against a budget of $10 million.
- The Cast Showoff: Diana Rigg does a rousing rendition of "You're the Top".
- Multiple Languages, Same Voice Actor: Peter Ustinov and Jane Birkin dubbed themselves for the French version. Ustinov also dubbed himself for the German version.
- The Shelf of Movie Languishment: The film was completed in 1979, but wasn't released until 1982.
- Uncredited Role: Barry Sadler was an uncredited writer.
- What Could Have Been:
- Carol Channing wanted to play Myra Gardener and the producers were eager to sign her on, but she could not because of theatre engagements, so Sylvia Miles was cast instead.
- Derek Jacobi was interested in playing Kenneth Marshall, but could not between his theatrical engagements and filming of Inside the Third Reich.
- You Look Familiar: Jane Birkin and Maggie Smith from Death on the Nile (1978) are back, but in different roles - as are Colin Blakely and Denis Quilley from Murder on the Orient Express (1974).
