- Fridge Logic: At the end of "The Bela Lugosi Blues," how were they supposed to explain Jack killing Moriah Thomas in self defense? Surely the courts wouldn't believe she was a vampire.
- In "Blood Ties," if the motive of the killers was to get organs from donors, why not shoot people in the head or neck to make sure they didn't damage anything they might need?
- Hilarious in Hindsight:
- In "The Roast," Tim Conway's character is recognized by someone as the voice of a cartoon character. That same year, Conway started voicing Barnacle Boy.
- In "Living on the Streets Can Be Murder," Bryan Cranston plays a homeless man named Walter.
- A popular joke among fans of Mannix was how the heck he kept shrugging off so many injuries on the job. Well, when your go-to doctor is Mark Sloan, one of the best doctors in the business, then you have yourself a fine explanation.
- More Popular Spinoff: It's this to Jake and the Fatman. It probably didn't help, however, that Jake and the Fatman was never rerun after its original broadcast on CBS.
- Narrowed It Down to the Guy I Recognize: One episode features Roma Downey and Corinne Bohrer as former sorority sisters of Amanda's, who are both suspects in the murder of a woman who was blackmailing them. Corinne's character turns out to be the murderer.
- Played with in "Discards," in which involves a group of ex-spies being hunted down, As shown on the main page, the guest stars played spies on TV... and the killer is played by Phil Morris, who also played a spy on TV - but in the 1980s on the revival of Mission: Impossible; he's the only one who didn't play a TV spy in the 1960s.
- Some Anvils Need to Be Dropped: "Murder in the Dark" had a surgeon being confronted over his alcoholism. Dick Van Dyke battled this disease himself.
- One episode dealt with the subject of hospitals intentionally delaying medical treatment, letting people die so they can save money.
- Tear Jerker: Much of The Movie Town Without Pity, as Mark and Steve try to both solve and come to terms with Carol's death. She'd had so many problems throughout her life, and she had finally straightened out and married someone she really loved; the video footage of her wedding showed them just how happy she was. And then she and her new husband were murdered. The end of the movie, where they scatter her ashes, is especially sad.
YMMV / Diagnosis: Murder