From the book:
- The description of how he cuts a prostitute in half just above her vagina with a chainsaw and she retains consciousness just long enough to watch him pull her legs away from her upper body.
- Patrick performs rat torture on a kidnapped woman by forcing a Habitrail tube into her vagina— using acid to widen the orifice— then forcing a starved rat to crawl into her vagina. He removes the tube and watches as the rat eats the restrained woman from the inside out... Not in the movie for obvious reasons.
- Some of the murder descriptions in the book are absolutely chilling, especially the deaths of Elizabeth and Christie.
- His description of himself near the end of the book and which also concluded the movie in a somewhat condensed fashion:
"There is an idea of a Patrick Bateman, some kind of abstraction, but there is no real me, only an entity, something illusory, and though I can hide my cold gaze and you can shake my hand and feel flesh gripping yours and maybe you can even sense our lifestyles are comparable: I simply am not there. It is hard for me to make sense on any given level. Myself is fabricated, an aberration. I am a noncontingent human being. My personality is sketchy, and unformed, my heartlessness goes deep and is persistent. My consciousness, my pity, my hopes disappeared a long time ago (probably at Harvard) if they ever existed. There are no more barriers to cross. All I have in common with the uncontrollable and the insane, the vicious and the evil, all the mayhem I have caused, and my utter indifference toward it, I have now surpassed. I still, though, hold on to one single bleak truth: no one is safe, nothing is redeemed. Yet I am blameless. Each model of human behavior must be assumed to have some validity. Is evil something you are? Or is it something you do? My pain is constant and sharp, and I do not hope for a better world for anyone. In fact, I want my pain to be inflicted on others. I want no one to escape. But even after admitting this - and I have, countless times, in just about every act I've committed - and coming face-to-face with these truths, there is no catharsis. My punishment continues to elude me, and I gain no deeper knowledge about myself. No new knowledge can be extracted from my telling. There has been no reason for me to tell you any of this. This confession has meant nothing."
- One interpretation of this is that Bateman has conveyed the entire story of the novel through the act of brutally murdering the reader. "But even after admitting this - and I have, countless times, in just about every act I've committed..."
- Patrick murders a child at the zoo by baiting him with cookies before stabbing him in the neck. The kicker is that the child doesn't actually die right away so Patrick pretends to be a doctor and ensures the death of the child in front of its panicking mother.
- In the case of Bethany, it was not only the horrific way she was murdered but the added 'you can never really know someone' aspect of it being a man she once dated.
- Bethany's death is so horrifying it loops around to being a Tear Jerker - she is the Woobie to end all Woobies. She is effectively crucified with a nail gun, then violently forced to give Patrick oral sex repeatedly. The last we hear of her is when Patrick mentions he has cut her left arm off - he uses it to morbidly disfigure her corpse, bashing her repeatedly in the face, causing it to cave in on itself.
- During a scene in which Patrick grinds up a woman's corpse into hamburgers and eats it, he muses that in his heart, he knows what he's doing is wrong, but then reminds himself that "this girl, this meat, is nothing". He knows what he's doing is wrong. He just doesn't care.
From the movie:
- The drawer of "implements" Patrick searches through. Among the more standard tools (knives, scalpels, and scissors) are a metal clothes hanger, a mousetrap, and a hole punch.
- Christie even tells Patrick the second time he goes see her that she had to go to surgery and probably needs to get a lawyer.