Gaffes

Snow starts and stops, depending upon the camera shot, when Knox is trying to convince Chris to attend the play with him.

When Todd receives the desk set for his birthday, and Neil and Todd go to throw it off the bridge, the desk set is clearly covered in plastic shrink wrap. However, when it is thrown, papers and pens still go flying everywhere.

When John Keating has the boys stand on his desk, he gathers his things to leave the room. Behind his desk (waiting to stand on it) are three boys on the left and none on the right. In the next shot of his desk, there are two boys on the left and two boys on the right.

At the study group that night, the boys are told to leave. Todd, who was supposed to be in his room because he said he didn't want to come, gets up and leaves with them.

At the studying group scene, Neil is wearing glasses. After Knox's arrival, there is no more trace of Neil's glasses.

The Thoreau quote read at the beginning of each meeting is incorrect. In fact, on close inspection, in the scene where Neil opens the book that Mr. Keating had placed on his desk, there is a visible ellipsis after some lines, indicating that the sentences had been taken out of context. However, it is indeed "I went to the woods because I wished to live deliberately", and not, as quoted in the film, "wanted".

The bagpiper in the first scene takes his pipes out of the case one moment and is seen playing "Scotland The Brave" during the ceremony apparently the next, without any indication any time had gone by. In reality it takes several minutes to tune a full set of pipes to the tonal qualities expected at a graduation (or similar).

In the first meeting of the Dead Poets Society when they are in the cave, Charlie Dalton shows a Playboy Magazine centerfold and then reads a poem I'm assuming he wrote on it. That style of centerfold did not come around until the 80's-90's.

After Mr Keating was fired he would have been escorted to collect his things and would not be given any access to the students.

When Knox calls Chris he hangs up when she picks up the phone, the sound of change being plunked down. In reality there would be no sound of chain since the recipient answered the call.

Keating's impression of Marlon Brando is not an anachronistic reference to Le parrain (1972) but to his role as Mark Antony in Jules César (1953).

During the convocation scene, the headmaster brags that over 75 percent of the school's graduates went on the "the Ivy League." It was stated here that in 1959, the Ivy League was only a five-year-old football conference and that the concept of the Ivy League as a specific group of select academic institutions was still many years into the future at this point.

However, on February 8, 1935, AP Sports editor Alan Gould first used the exact term "Ivy League." [From Mark Bernstein, Football: The Ivy League Origins of an American Obsession, University of Pennsylvania, 2001]

The school's name is Welton throughout the movie. Various characters call the school "Hell-ton" including the cafeteria's offering of "Hell-ton Hash". It's not a mistake about the name of the school, just boys making fun of their school.

The first meeting of the Dead Poets Society in the cave is at night but there is light through the hole in the ceiling.

Mr Keating is clearly older than 33.

The boys have read Latin before, and yet in their first Latin class of the year, they recite feminine nouns of the first declination which is typically the first thing you learn in Latin, and also the easiest.

In the "carpe diem" scene, when Mr Keating says that alumni of Wellton from the turn of the century pictured are all dead and therefore to use one's time effectively. However, assuming most of said students were 17-18 in those photos, they would be in their mid to late 70s in 1959. It is therefore very feasible that some would still be alive when Mr Keating makes his speech.

In the end credits listing music entries, George Frideric Handel Suite No. III in D Major is false. The Suite played has No. 2.

When the Dead Poets learn of Neal Perry's suicide, they take a walk in the snow. There should be six remaining Dead Poets, but only five are shown walking; one is missing without explanation.

Mr. Keating's comments when looking at the pictures of the old classes..

Although set in 1959, the chemistry textbook the students use, "Chemistry: A Modern Course" by Robert Smoot, is copyrighted 1987.

Although the film is set in 1959, the tune played by the lone bagpiper by the lake is "The Fields of Athenry." This tune, though considered a classic Irish folk tune, was only written in 1979.

Many mistakes in the band musical instruments used for 1959. Fiberglass sousaphones, metal drum carriers, tenor drums - all about 20 years too early.

The desk set given to Todd is packaged in shrink-wrap, invented in the 1970s.

The goals used in the soccer practice scene are more modern than what would have been used in 1959.

Near the beginning, starlings honk like geese.

After Keating instructs the boys to rip out the introduction to their poetry textbook, his lip movements do not match the speech.

The line that Keating refers to from Walt Whitman's poem "Song of Myself" is misquoted. The line actually reads "I sound my barbaric yawp over the roofs of the world".

When Neil first learns that Todd Anderson is rooming with him and that Todd's brother went to Wellton, he says, 'oh, so you're that Henderson.'

When Mr. Nolan is interrogating the boys after Neil's death, Cameron makes the claim that if it weren't for Mr. Keating, Neil would be up in his room studying chemistry. However, Neil had already stated in an earlier scene that he took chemistry over the summer because his father thought it would be a good idea to get ahead in his studies.

After the welcoming speech, Todd's father refers to the headmaster as "Dr. Nolan". Everyone else throughout the movie calls him "Mr. Nolan".

A teacher who had resigned or been dismissed in disgrace would not be allowed to enter his classroom while class was in session. Nolan would either have gathered his possessions for him, or ordered him to wait to do it.