[[quoteright:350:https://static.tvtropes.org/pmwiki/pub/images/one_flew_over_the_cuckoos_nest.jpg]]
[[caption-width-right:350:Mac is given electroshock therapy.]]

'''As a Moments subpage, all spoilers are unmarked [[Administrivia/SpoilersOff as per policy.]] Administrivia/YouHaveBeenWarned.'''
----
!!The novel
* Bromden's…dream…hallucination…[[{{MindScrew}} reality]]…whatever that thing was when he didn't take his pills one night. It's a strange, ''Franchise/SilentHill''-esque sequence where a wall opens up to reveal a large mechanical slaughterhouse where workers move patients around on hooks and slice them open, where upon they bleed rust and ashes. In the true horror fashion, the old Chronic mental patient that Bromden saw get sliced open and mechanically bled out really is dead the next morning.
* The description of the patient who was an angry lunatic before, but became an empty shell after his lobotomy. His eyes are described as being like burnt-out lightbulbs...
** Also the realization that giving unruly patients lobotomies was standard operating procedure at the time, so that a lot of people with relatively minor emotional problems wound up in nearly vegetative states as a result of their "treatment."
** Worst of all, this is what happens to ''[=McMurphy=] himself'' after he attacks Ratched for driving Billy to suicide. Chief, unwilling to let his friend live on like this, gives him a MercyKill.
* The [[RapeAsDrama rape of patients]] by the orderlies... just the knowledge of the patients, who are largely helpless, being forcibly raped while being completely unable to defend themselves (and this is going on ''with all the nurses knowing'') is utterly scary.
** It's important to remember that [[UnreliableNarrator Chief Bromden is a schizophrenic who occasionally has fantastic hallucinations and never shows the ability to discern them from reality]] (see the very first scene, where he describes the Nurse transforming into a [[EldritchAbomination many-tentacled beast]] and attacking the three orderlies in a physically-impossible manner). It is entirely possible that the whole rape idea is another example of Bromden exaggerating the level of menace in his handlers to bizarre proportions, as this is a characteristic he displays consistently throughout the book almost every time he describes any person of authority, at least until after [=McMurphy=] helps Bromden regain his self-confidence.

!!The movie
* The Electroshock scene, it actually looked like they shocked Jack for real.
* Nurse Ratched. As ''Series/TheRottenTomatoesShow'' put it, she has so much power in this movie that you get nervous just ''talking'' about her!
* Stuff that was occurring on site, as the film was being made, was pretty terrible. A group of politicians visited the hospital in 2004 and stumbled upon a room containing the cremated remains of '''''3,500 people''''' in copper canisters who died between the 1880s and the 1970s. The hospital was demolished in 2008[[http://www.nydailynews.com/news/world/hospital-immortalized-flew-cuckoo-nest-torn-article-1.349961]] and replaced with a much better facility.
----