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.
The books and release dates are as follows:
10. 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.
14. 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.
15. 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.
16. 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.
18. 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.
19. 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.
21. Claudia and the Recipe for Danger (August 1995) - Claudia and Mary Anne enter a baking contest, but someone doesn't want them to win.
23. 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.
24. 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.
25. 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.
26. 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.
27. 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.
28. Abby and the Mystery Baby (February 1997) - Abby's family takes in a baby left on their porch while authorities look for the parents.
31. 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.
32. Claudia and the Mystery in the Painting (October 1997) - Claudia must search for paintings that everyone swears the artist destroyed before her death.
33. Stacey and the Stolen Hearts (February 1998) - Someone steals a bag of valentine-grams and begins revealing the very personal content on them.
34. 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.
35. 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.
36. 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.