Scholastic and Ann M. Martin began releasing BSC Mysteries along with the regular books starting in 1991.
The books are very similar to the regular series, with the only difference being that the baby sitters are usually caught up in solving a minor mystery. In 2022, a reprint of The Mystery at Claudia's House has a release date of April 4, 2023 on Amazon. The first five books have been released exclusively at Walmart.
The books and release dates are as follows:
- Stacey and the Missing Ring (August 1991) - Stacey is accused of stealing a ring while babysitting.
- Beware, Dawn (November 1991) - Dawn receives threatening notes and phone calls while babysitting, all while competing for Sitter of the Month.
- Mallory and the Ghost Cat (February 1992) - Mallory finds a potential "ghost" cat.
- Kristy and the Missing Child (May 1992) - Jake Kuhn is reported missing, and Kristy was the last person to see him.
- Mary Anne and the Secret in the Attic (August 1992) - Mary Anne finds out the truth about her past.
- The Mystery at Claudia's House (November 1992) - Weird things are happening to the Kishi family when Claudia's room is ransacked and her sister is caught lying to their parents.
- Dawn and the Disappearing Dogs (February 1993) - Dawn's pet-sitting charge and Kristy's puppy go missing, and the babysitters know it's more than a coincidence
- Jessi and the Jewel Thieves (April 1993) - Jessi visits her friend Quint in New York City and when they overhear two men discussing a jewel heist, they have to investigate.
- Kristy and the Haunted Mansion (June 1993)- Kristy, Bart, Charlie and the all star softball team the Krashers' get caught in a storm and spend a night in a haunted mansion.
- Stacey and the Mystery Money (August 1993) - There's counterfeiting going on in Stoneybrook and, when Stacey ends up accidentally paying someone fake money, the Baby-sitters club have to clear her name.
- Claudia and the Mystery at the Museum (November 1993) - Claudia is visiting Stoneybrook's new museum when several thefts occur. Claudia has to find the culprit and save the museum.
- Dawn and the Surfer Ghost (December 1993) - Strange things are happening when Dawn sees a ghost off the California coast.
- Mary Anne and the Library Mystery (February 1994)- Mary Anne gets a job helping with the children's read-a-thon at Stoneybrook Public Library, where someone is setting books on fire. But who?
- Stacey and the Mystery at the Mall (April 1994) - The babysitters are working at the Washington Mall for a class, and they begin to wonder if it's safe to shop there after a string of expensive thefts happen.
- Kristy and the Vampires (June 1994) - Accidents, mysterious letters, and rivalries on the set of a TV movie being shot in Stoneybrook add up to trouble for Kristy.
- Claudia and the Clue in the Photograph (August 1994) - Claudia unknowingly takes pictures of a bank robbery in progress that end up being the only clues to catch the crooks.
- Dawn and the Halloween Mystery (October 1994) - Trick-or-treating is called off after a robbery in Dawn's neighborhood, unless the We Love Kids Club can catch the robber.
- Stacey and the Mystery at the Empty House (December 1994) - Stacey is house sitting while the Johanssens are away, only to begin suspecting she is not alone.
- Kristy and the Missing Fortune (February 1995) - Kristy digs into Stoneybrook's past and discovers the story of a young heiress who disappeared and took her fortune with her.
- Mary Anne and the Zoo Mystery (April 1995) - A school trip takes Mary Anne to the zoo and a mystery arises when they discover someone has been letting animals out of their cages.
- Claudia and the Recipe for Danger (August 1995) - Claudia and Mary Anne enter a baking contest, but someone doesn't want them to win.
- Stacey and the Haunted Masquerade (October 1995) - Strange things are happening at Stoneybrook Middle School as Stacey helps plan a Halloween dance.
- Abby and the Secret Society (February 1996) Abby attempts to solve a murder that is somehow tied to the shady past of the old country club, where she gets a part-time job.
- Mary Anne and the Silent Witness (April 1996) Mary Anne discovers that her babysitting charge has witnessed a robbery, but is scared to tell anyone about it.
- Kristy and the Middle School Vandal (June 1996) Kristy attempts to discover who vandalized the school, while the Baby-sitters club tries to win a mystery war.
- Dawn Schafer, Undercover Baby-sitter (October 1996) Dawn babysits for a family feuding over an inheritance, and attempts to bring the family together by helping them solve the mystery.
- Claudia and the Lighthouse Ghost (December 1996) - Old friends of the Kishi family come to stay, which unveils a terrible story that happened a long time ago at the old Stoneybrook lighthouse.
- Abby and the Mystery Baby (February 1997) - Abby's family takes in a baby left on their porch while authorities look for the parents.
- Stacey and the Fashion Victim (April 1997) - Accidents and threatening notes plague Bellair's Fashion Week, and Stacey must figure out who is behind it.
- Kristy and the Mystery Train (June 1997) - Three babysitters embark on a mystery tour with child star Derek Masters , but someone is determined to ruin their good time.
- Mary Anne and the Music Box Secret (August 1997) - Mary Anne finds a package hidden in the basement of her grandparents' house. Ignoring the curse written on the packaging, she opens it to discover a beautiful music box, just before odd things begin happening.
- Claudia and the Mystery in the Painting (October 1997) - Claudia must search for paintings that everyone swears the artist destroyed before her death.
- Stacey and the Stolen Hearts (February 1998) - Someone steals a bag of valentine-grams and begins revealing the very personal content on them.
- Mary Anne and the Haunted Bookstore (April 1998) - Mary Anne gets a job at a bookstore, only to discover happenings that aren't just fiction.
- Abby and the Notorious Neighbor (June 1998) - Abby becomes convinced that her neighbor is a thief, and tries to gather evidence to take to the police.
- Kristy and the Cat Burglar (August 1998) - When a cat burglar strikes a Stoneybrook mansion, Kristy and her friends must work to solve the crime before the thief gets away.