Standard compact disc (CD) and digital video disc (DVD) dimensions are roughly 12.5 cm (5 inches) in diameter. Smaller optical media, a mini CD, reduces the diameter closer to 7.5 cm (3 inches). Apple MacBook computers are equipped with slot-loading optical drives, and if you insert a mini CD it will not play. You even run the risk of lodging the mini CD in your MacBook permanently. There are options to access the contents of a mini CD, but you may need to be resourceful.
Use an adapter
Adapt the 7.5 cm (3 inch) mini CD factor to a standard 12.5 cm (5 inch) platter. Memorex made adaptors for mini CD sized media to fit in a regular CD player. These have been discontinued, but an adaptor could be found on eBay or constructed at home.
Insert your mini CD into the adaptor. The mini CD should snap into the middle of the adaptor platter.
Insert the adaptor into the optical drive slot on your MacBook. The adaptor unit will insert and eject from your MacBook just as an ordinary media disk would.
Use a different CD drive
Connect an external universal serial bus (USB) or firewire drive to your MacBook. If an adaptor cannot be found, you can read a mini CD with an external drive. Any USB or firewire CD drive should support 7.5 cm (3 inch) mini CD media, as long as the drive is tray-loading.
Find a friend with a tray-loading CD player on their computer. Most desktop computers will have such drives, and some laptops will. Ask your friend if they can mount your mini CD and copy the contents.
Take it into an Apple retail outlet. Make an appointment at the Genius Bar of your local Apple Store, and bring in the mini CD and your MacBook. The Genius should be able to assist you with copying the contents to your computer.
Do not attempt to insert a mini CD into the slot of your MacBook without an adaptor. It could easily get stuck and require a costly repair.