- Alas, Poor Scrappy: Ellen's death.
- Also toyed with when the death of Nathan's daughter was probably one of the few rare times the audience felt any sympathy for him.
- Big-Lipped Alligator Moment: Tends to happen in the more recent series, from 2007-2008 onwards.
- Bizarro Episode: Almost once a series this happens.
- Ear Worm: Woe betide you if you live in Britain and you can't hum the Theme Tune.
- Ensemble Darkhorse: Charlie Fairhead, who went from playing hockey in the corridors to becoming, by Word of God, the show's most important character.
- Big Mac.
- Connie Beauchamp, who enjoyed similar popularity during her time on sister show Holby City. Fan reaction when it was announced that she would become a regular on Casualty almost four years after her last Holby City appearance can best be described as rapturous.
- Genius Bonus: In one episode, a dispatch with a Scottish accent sends Nikki and Comfort to St. Aloysius' Church. St. Aloysius College is a well-known Catholic independent school in Glasgow.
- Heartwarming Moment: Downplayed a little. Patrick, after his and Lara's moment gets killed again.
Max: Lara, I need you. (she leaves).Patrick: You're not the only one, Max.
- Hilarious in Hindsight: Charlie and Baz's Ross-and-Rachel like relationship is compounded by having Baz briefly date a posh bloke called Charles for one episode. Charlie suggesting that they be "friends who sleep together sometimes" could also be likenened to the episode where Monica and Richard try to be friends.
- Les Yay: Selena and Maggie.
- One of Us: Nathan:
"Lots of very respectable people are trekkies."
- Sending Stuff to Save the Show: Slightly subverted, rather more a case of Fandom to get incidental characters into full-time characters.
- They Changed It, Now It Sucks: The Re Tool seems to have resulted in this in the opinion of some fans. You only have to look at the ratings to see that it's not what it was.
- What An Idiot: Guppy snorting some heroin he stole from a patient because he thought it was cocaine.