This special begins, when Linus calls the Brown house, and Sally picks up. She gets so excited that her "Sweet Babboo" is on the other line. Linus denies that he is her Sweet Babboo, and tries to ask if Charlie Brown is home, but while he is trying to ask that, Sally asks if he called to ask her to a movie. Linus gets furious, and yells at her, saying, he will not be taking her to a movie, and only called because he wants to talk to her brother. Sally misinterprets this, and tells him she will be waiting outside for him to pick her up for the movie. She then gives the phone to Charlie Brown.
Linus tells Charlie Brown he has to tell him something important and will be over right away. When he arrives at Charlie Brown's house, he tells him his family will have to move, due to his father's job transfer. Charlie Brown is shocked to find out about this.
Lucy then goes to Schroeder to tell him the same thing Linus told Charlie Brown, and she gives him a picture of her so he will always remember her. Schroeder however, does not take Lucy so seriously, and tells her that he would want to forget her if she left.
Charlie Brown then sadly watches the moving men take the Van Pelt's stuff, and load them into their trucks. Charlie Brown then goes to Lucy's psychiatry booth, and tells her he will be so upset without Linus. Lucy then yells at him, and reminds him that she is also leaving. Lucy then shows Charlie Brown the new owner of the psychiatry booth (Snoopy), who changes the cost of the booth from 5 cents, to 50 cents.
Lucy then walks over to the Brown house, and finds Sally waiting in front of the house, saying she is waiting for Linus to take her to the movie. Lucy tells Sally that her family is moving, and Linus is not coming, but Sally refuses to believe this.
Linus then invites Charlie Brown to his and Lucy's going away party. Charlie Brown asks Sally if she wants to come, but Sally insists that Linus is going to pick her up and take her to a movie. The Van Pelt going away party is catered by Joe Cool, who serves everybody dog food.
The next day, Linus and Lucy say their sad good-byes to Charlie Brown. As the Van Pelts pull out of their driveway, Linus throws Charlie Brown his security blanket, as a way to remember him. After the Van Pelts leave, Charlie Brown walks home sadly.
When Charlie Brown gets home, Sally is sitting on the porch, still waiting for Linus to take her to a movie. Charlie Brown tells her that Linus and his family have moved away. Sally walks inside angrily. Schroeder comes and asks where Lucy is, Charlie Brown tells him she and her family have moved away. Schroeder tells Charlie Brown that he thought she was kidding when she told him she was moving, then he grows upset, and says, "I never even said good bye".
Later, Charlie Brown finds a picture postcard in his mailbox. Linus, and Lucy sent it to him. After reading it, Charlie Brown sadly says, "That's the saddest postcard I ever read." Back at Schroeder's house Schroeder is playing his toy piano, but Lucy's face appears on the staff, that makes him stop playing, and say, "Don't tell me I've grown accustomed to *that* face."
The next day, Charlie Brown tells Peppermint Patty, that he is so upset that Linus moved away. Peppermint Patty tells Marcie that they have to help Charlie Brown get over his sadness. Marcie asks Peppermint Patty if she likes Charlie Brown, Peppermint Patty naturally denies it. She then walks home trying to convince herself that she could never like a loser like Charlie Brown.
That night while Peppermint Patty is trying to sleep, she thinks Charlie Brown is probably feeling bad for himself, and she decides to call him to make him feel better. When she calls him, Charlie Brown is so tired, that he does not seem to listen to what Peppermint Patty is saying to him. Peppermint Patty invites him on a date to the movies, but makes it seem like Charlie Brown is the one asking her, and not the other way around. She then tells him that she will go with him to a movie, then hangs up, and goes to sleep feeling good about herself. Charlie Brown then suddenly wakes up, and wonders what he is doing by the phone, and says that he just dreamt he was talking to Peppermint Patty.
The next day, Peppermint Patty is waiting for Charlie Brown to pick her up for their date, and tells Marcie about her plans with Charlie Brown for the day. Marcie then goes to Charlie Brown at the wall, and asks him why he looks so tired. Charlie Brown tells her that for some strange reason, last night he woke up in the middle of the night by the phone, and had just dreamt he spoke to Peppermint Patty. Marcie realizes what is going on, and goes to tell Patty, that Charlie Brown is not coming. Patty however does not believe Marcie, and continues waiting.
Later that day, Peppermint Patty calls Charlie Brown to tell him she is angry he did not show up to take her on their date. She continues bothering Charlie Brown, but says she will not take revenge on him, and when they hang up, Charlie Brown says "I never know what's going on".
The special ends when Charlie Brown notices moving trucks in front of the Van Pelt house again. He looks to see what is going on, and he is excited to find Linus. Linus tells him his father did not like his new job and they moved back. Just then Lucy walks out of the car and says "What kind of a neighborhood is this? It didn't change a bit", to which Linus says, "Oh yeah. She's back too".
- This is the third time Snoopy says "Hey!", the previous two times being He's Your Dog, Charlie Brown and It's the Easter Beagle, Charlie Brown.
- It is unknown why Rerun is not in the car when the Van Pelts leave or in any part of the special despite him being a character in the specials and comic strip already.
- The scene where Schroeder plays a tune and Lucy's face appears on the notes was also seen in Play It Again, Charlie Brown.
- The primary storyline for Is This Goodbye, Charlie Brown? is based on newspaper strips which first appeared between May 9 and May 21, 1966. These are reprinted in the books The Unsinkable Charlie Brown and volume 8 of The Complete Peanuts.
- The faces of Mr. and Mrs. van Pelt are briefly visible when the car pulls out of the driveway, making this the only time that a major character's parents (other than Snoopy's) were ever depicted. The moving people as well are briefly shown.
- This is the second piece of animated material in which Linus gives up his blanket (the first time being in A Boy Named Charlie Brown). This time, he does not seem to go through major withdrawal or feel sorry for giving it up.
- The original broadcast of this special was pre-empted in Tampa, Florida, as WTVT (at the time affiliated with CBS) aired a Three's Company repeat instead.
- This special was nominated for the Emmy Award for Outstanding Animated Program (as was What Have We Learned, Charlie Brown?).
- Brad Kesten – Charlie Brown
- Jeremy Schoenberg – Linus van Pelt
- Angela Lee – Lucy van Pelt
- Michael Dockery – Marcie/Shermy
- Stacy Heather Tolkin – Sally Brown
- Victoria Vargas – Peppermint Patty
- Kevin Brando – Schroeder/Franklin
- Bill Melendez – Snoopy
- Is This Goodbye, Charlie Brown? on the Internet Movie Database.
- Is This Goodbye, Charlie Brown? on the Big Cartoon Database.
- Is This Goodbye, Charlie Brown? on AllMovie.