Peppermint Patty and Marcie are voiced by male actors.

Vince Guaraldi sung the vocals for the song "Little Birdie", one of the rare moments he lended his voice to the music he created for the Peanuts specials, the other being "Joe Cool" in "You're Not Elected Charlie Brown" from 1972.

Lucy appears only at the beginning of the film when she is playing football with Charlie Brown. After that she disappears for the rest of the movie.

Snoopy's fight with the folding lounge chair appears to have been inspired by W. C. Fields' similar struggle with a chair in 1934's "It's A Gift."

The only other Thanksgiving-related special in Peanuts media is "This is America, Charlie Brown," about the Pilgrims' voyage to Plymouth with all characters portraying the Pilgrims themselves.

Continuity

The sundaes on the table during dinner disappear and reappear between scenes.

During the Thanksgiving "dinner" scene, Peppermint Patty's plate of food disappears and reappears after Snoopy serves her.

While Snoopy, Linus, and Charlie Brown are cooking the fake Thanksgiving meal, two bowls of pretzels are shown. They're the folded type. Later during the meal, they change to pretzel sticks.

As Franklin sits alone on the opposite side of the table from which Snoopy serves "dinner", empty chairs adjacent to him disappear and reappear.

The plates Snoopy set out when he initially set up the ping-pong table disappear in front of all guests except the first person he tosses a plate to when serving everyone.



Factual errors

A scene shows Charlie Brown checking to see if he's gotten any mail. However, there is never any mail delivery in the U.S. on Thanksgiving Day due to it being a federal holiday.

Marcie calls Charlie & Peppermint Patty : "Miles & Priscilla". Referring to Pilgrims "Priscilla Mullins", "John Alden" and Myles Standish.". It's been said that the story was true about the romance/ love triangle , but the historical evidence is inconclusive.



Incorrectly regarded as goofs

When Charlie Brown states that Thanksgiving is upon them, Sally shouts that she hadn't finished eating all her Halloween candy. She never had Halloween candy during the events of "It's the Great Pumpkin, Charlie Brown." However, "It's the Great Pumpkin, Charlie Brown" took place in 1966, and clearly Sally would have gone trick-or-treating in any ensuing years afterwards.



Plot holes

It is puzzling why Snoopy did not serve the turkey and pumpkin pie to Charlie Brown's guests rather than saving them for himself and Woodstock. Serving to the guests would have been truer to the spirit of Thanksgiving and the two would have simply eaten the leftovers.