* AlternativeCharacterInterpretation: Porter [[spoiler: infecting the two survivors and escaping at the end of ''Patient Zero''. Was he killing them so that he could start over clean, or was he MaddenedIntoMisanthropy by his treatment in the facility?]]
* BestKnownForTheFanservice: The sex scene between Paul and Marcy is even OnThisVeryWiki one of the more memorable parts of the movie. Partly because it does come a little out of nowhere[[note]]Though this is partly due to some other scenes foreshadowing Marcy and Paul growing closer getting cut[[/note]]. Behind the scenes, the most memorable detail also comes from this scene - where Cerina Vincent only allowed one inch of her ass shown on screen and the rest taped with a bedsheet.
* BigLippedAlligatorMoment: The "PANCAKES!" scene and the rabbit surgeon. Big surprise the first one was added in at the last minute when Eli Roth saw the little kid practicing tae kwon do.
* EnsembleDarkhorse:
** Bert tends to be the most popular of the college kids amongst fans.
** Deputy Winston, the party cop, counts as well.
** How can you forget [[CoolOldGuy Old Man Cadwell]]?
* HarsherInHindsight: Inverted. Marcy's monologue where she compares her situation to "being on a plane that you know is gonna crash" would've almost certainly resonated far stronger with the audience when the film premiered - only a year after 9/11. The audition date was actually on 9/11 and ''that'' was the scene that had to be read.
* InferredHolocaust:
** [[spoiler: The last shot is of the first shown victim lying in the river and bleeding into the water. It pans over to a truck of bottled water, presumably filled with CoolClearWater (see above) from the river.]]
** The sequel's ending animation shows a trucker drinking Down Home Spring Water. He pees in the bottle and throws it at some dumb kids in a convertible. [[spoiler:The kids are heading to New Orleans for Mardi Gras.]]
* MemeticMutation:
** PANCAKES!
** "Ooooh! Faced!"
* NauseaFuel: A lot. Why do you ask? The disease from this movie was even voted Number One on The Most Deadliest Movie Diseases.
* OneSceneWonder: Dennis just appears in three scenes but of course his "pancakes!" scene is the most remembered part of the movie.
* SignatureScene:
** Dennis's scene for its pure randomness.
** The leg shaving scene. [[{{Squick}} BAR NONE]].
* {{Sequelitis}}: So bad that the director refuses to be associated with it.
* SpecialEffectsFailure: [[spoiler: After John cuts off his hand in ''Spring Fever'', Cassie covers up the stump with duct tape. It's clearly his fist wrapped up and him holding his arm slightly back to make it look shorter.]]
* {{Squick}}: A lot. Why do you ask? This is made about a million times worse by the clear connection between the flesh-eating disease and sex.
* ViewerGenderConfusion:
** The "Pancakes" kid is a boy, named Dennis. However he has very long hair and is apparently prepubescent, so many people mistook him for a girl.
** Some viewers found the first sex scene a little confusing, specifically in terms of what Marcy was doing to Jeff ''from behind'' to provoke such a strong reaction from him. The confusion lead some people to theorize that [[AlternateCharacterInterpretation Marcy might have been a pre-op trans woman]]. [[note]]The generally accepted consensus is that she was actually sticking her finger up his asshole.[[/note]]
* WhatAnIdiot: Winston. Aside from being creepy as fuck, he does not seem to think clearly either. A sick and disoriented [[spoiler:Paul]] encountered Winston partying in the forest, and knocked him out when he heard that all infected persons are to be shot on sight. He then stumbled onto the highway, and a truck-driver took him to that local doctor's office, where the police located him. As he was too sick to talk, he could not communicate to the officers that one of the infected bodies had fallen into the local water reservoir, and hence infected it. To find out what he tries to say, the doctors advise that the police brings him to the county hospital, who actually has the capabilities to treat the flesh-eating bacteria. Deputy Winston is chosen to transport him there. Yet, he is vengeful for being hit over the head by him earlier.
** '''You'd expect:''' That he will complete his task without hesitating. [[spoiler:Paul]] is quite possibly the key for scientists to analyse this virus further so they are prepared for future infections. Apart from that, [[spoiler:Paul]] still has something '''very''' important to say.
** '''Instead:''' He doesn't give a shit. He is only out for revenge, and dumps [[spoiler:Paul]] [[DownerEnding in the closest river]]. [[AndThatsTerrible And that was bloody stupid]]. He pretty much is solely responsible for everything that happened in the sequel and [[InferredHolocaust after that]]. He actually dumped a guy with a highly aggressive and quickly spreading bacterial infection in a river, which co-incidentally leads back to that town and the CoolClearWater bottling factory. He should really have known that. Apart from that, there wasn't much of a reason in the first place. Oh, [[KarmaHoudini and he got away with it]].