There are many comics in the Sibling Rivalries series that have been cancelled and scrapped, mainly because the author may have lost interest mid-comic. Below is a list of all of the known cancelled comics.
- Sibling Rivalries: Vancouver Stories 2: A sequel to Sibling Rivalries: Vancouver Stories which continues the adventures of Jason Parker as his second football season begins. Although the author loved the idea of a sequel at first, he eventually gave up writing near the beginning, because he did not know how the comic could go on.
- "Diamond Deal Disruption": Basically this comic was a prototype version of "Diamonds in the Rough". In this comic, Joel Gonzales asks Packie to steal some diamonds for him. This comic was replaced by "The Big Trade-Off".
- "Super Taffy Tantrum": Packie is accused of stealing a shipment of taffy from a factory. This comic was replaced by "San Salvador's Story".
- "Fashion Disaster!": Packie buys some fancy clothes, which makes him very popular at school. However, Joel knocks him out and steals his clothes, leaving Packie in his underwear. This comic was replaced by "Yearning to be Young". The comic was scrapped mainly due to a rather disgusting scene that pretty much ruined the entire comic.
- "Super Bowl XLVIII": The comic's overall plot is unknown, although it would be released around the time of Super Bowl XLVIII in 2014, and could possibly be focused on Gerry. This comic was replaced by "Love is What Makes the World Go 'Round".
- "The Real Patrick McReary": The comic's overall plot is unknown, although its title is a reference to The Real Slim Shady, a song performed by Eminem. This comic was replaced by "McReary TV", which also ended up being scrapped.
- "McReary TV": The McReary siblings get their own TV show, which explores their lives at home and school. This comic was replaced by "Best Brother".
- "Bienvenidos, Esteven Caballero!": A teenager named Esteven Caballero is sent by Joel Gonzales and Giovanni Ancelotti to play tricks on Packie, much to his annoyance. This comic was replaced by "Not Afraid (Of Losing My Concert Tickets)", and the character Esteven Caballero would later be reused with a different personality in Sibling Rivalries: Vancouver Stories.
- Unknown Title: After discovering that the McReary family got a new dog, Anti-Steve, Anti-Cutecumber, and Anti-Steve Jr. steal the dog so they can turn it evil. This comic was replaced by "Field Trip Gone Wrong!", and it was scrapped since it was too over-the-top for the series (which is supposed to be realistic-fiction).
- "A McReary Family Christmas": When Joel Gonzales and James Johnson try to ruin Christmas, it is up to Packie and his siblings to save the holiday for everyone. Meanwhile, Kate hopes to get her first kiss from her boyfriend Salvador Real. This comic was replaced by "House Party", although the author made a new Christmas comic in 2015 titled "A Christmas Story", which is in Season 5. The new Christmas comic has a much different plot than this scrapped comic.
- "The Squad Of The School": Packie starts hanging out with a group of kids at school, which upsets Francis and the other siblings, who fear that Packie may replace them. This comic was replaced by "Into The Second Dimension", written six months later.
- "Sleepover At San Salvador's": San Salvador invites the McReary siblings over for a sleepover, which consists of a night filled with wild and crazy surprises. This comic was replaced by "Like Father, Like Sons (And Daughter)".
- "Just My Luck": Packie reveals that he does not believe in bad luck, but when Friday The 13th comes around, he experiences lots of bad luck, and must find a cure. This comic was replaced by "Portrait of a Football Player".
- "Six and a Half Siblings": After fighting with his brother, Jose Gonzales decides to stay with the McRearys for a while. However, the siblings later try to convince him to go back to his house and make up with Joel. This comic was replaced by "The Amnesia Act of 2015", although the basic concept of the comic would later be reused for the Season 5 comic "Uncle Cameron Moves In".
- "A Christmas Story" (Original Version): On Christmas, Kate and Salvador are surprised to see that they are each other's Secret Santas. Despite things being awkward between them ever since break up in an earlier comic, they still remain friends. This version of the comic was scrapped, and it was replaced by the final version of "A Christmas Story".